Approach to developing mobile application that supports a web application - iphone

My company built its own project management web application. It's like basecamp on steroids. The core features of this application are:
create task lists
assign tasks to team members
track hours against task items
I am looking to build mobile application(s) as an extension to the web application. The mobile applications(s) must:
reproduce the features mentioned above
connect to the same database as the web application
retain drag drop capabilities
provide a rich user experience equivalent to or better than the web application
work on iphone, droid and blackberry
Given the requirements above, how should I approach the development of this mobile application? There's about 20 smart phone users in my company: 8 iphones, 7 droids and 5 blackberries.
I've heard of development frameworks like Phonegap that allow you to develop in HTML, Javascript and CSS. The software then works cross platform across blackberry, iphone and droid. If I am an average/slightly-above-average programmer, will I be able to build a high quality cross platform mobile application with PhoneGap (or another x platform development framework) that meets the above requirements?
Or should I build each iphone, droid and blackberry application independently?
What's the best approach? What are the trade offs?


John,
Well it sounds like you've got a bit of work ahead of you! When you have an existing web-based application, there are two basic approaches to getting your app available on any particular device: you can (1) write a native app that implements the functionality you want for each device you want to support or you can (2) write a web-based "wrapper" for your existing app and serve the content as HTML/CSS to those same devices.
Option 1: Build a native app for each platform you want to support
As for the first approach, the benefits can be great. By using each device's native frameworks, you have the complete ability and flexibility to take advantage of the best features of each device. Your app's views can also render faster, since all you will be fetching from your server is the data to populate the views with (i.e., you do not have to load images, HTML templates, or CSS files at all).
The drawback with this approach is that it inherently requires each device to have its own application. So if you're supporting a web app, an iPhone app, an Android app, and a Blackberry app this means that you have 4 completely separate codebases to maintain. If you add some sort of new feature to your web app (which you presumably will at some point), you will also have to implement that new feature in the three other separate code bases. Given the fact that these devices can have different interaction models, this could pose a challenge. Another drawback here can be distribution (i.e., you may have to go through a review process for something like the iPhone app store depending on how you want to distribute your app). It also means that the amount you will have to learn is quite a bit greater since each device has its own API set and programming "philosophy".
Option 2: Write a web-based "wrapper" for your app (perhaps using a library)
This approach also has a great deal of benefits. First off, if you use a framework like PhoneGap or Sencha Touch or Rhomobile, the big benefit is that you theoretically write the "mobile app" code once and it works across each of the devices supported by the framework. Compared to writing a native app for three platforms, this is a lot less work.
Downsides here are as follows. This approach runs as a website in the device's browser, so you will not have access to all of the functionality of every device. All of the great stuff in the iOS and Android API's will by definition not be available to you. You are also somewhat limited here with regard to local storage, but this may not be a great concern to you given your web app. Another drawback is that there will be more bandwidth required from your server this way, since you are serving all of the HTML, images, and CSS that you would otherwise not have to with a native app. Depending on the number of users and complexity of the pages, this could be significant to you or not. Another downside here is that you cannot go full-screen (with the iPhone in Mobile Safari for instance there is always a toolbar at the bottom).
General Concerns
One thing that concerned me reading your question was your list of requirements. Reproducing features and connecting to a remote data store are things you can definitely do with both native and web-based mobile apps. But "retain[ing] drag drop capabilities" is not. With an iPhone, for instance, you can use handles in a UITableViewCell to provide a way to reorder lists, but full-on drag-and-drop is not really something that fits with a mobile device's user interaction model. You may have to re-think this one.
The requirement to "provide a rich user experience equivalent to or better than the web application" is also a bit troubling. While phone-based apps can have really streamlined ways to get at and manipulate data, remember that you are designing for a screen that is a few inches square. It is physically impossible to provide the same breadth of information in an organized manner than you can with a 21" HD widescreen monitor.
Remember that you're designing here for mobile, so you want to take advantage of the available platforms but remember that you're dealing with small screens and limited interaction methods (touches, swipes, and gestures).
My recommendation is that if this is your first time at this, you want to support all of these devices, and you already have experience with the web, I would suggest taking Option 2 and using one of the above-mentioned frameworks. It would be the easiest way to start and there wouldn't be any radically different concepts for you to have to learn.
Good luck!


An additionally comment on what Neal L posted above, with Rhomobile you can access the devices native capabilities as well as have drag and drop in your views.
There are several training and example videos here: http://rhomobile.com/webinars/

Related

HTML5 web app vs Native mobile apps

Hi I have been recently exploring some of the Javascript mobile frameworks that can be used for developing mobile web apps like Sencha, JQTouch, JQuery mobile etc.
I know the adv and disadvantages of both.
I just need some recent stats which show the market's adoption or opinion.

I tried three ways to develop mobile applications.
First method is to use frameworks that will take your html/css/js files and package them into mobile applications depending on your targets (BlackBerry, iPhone, Android, ...). I used PhoneGap (known today as Cordova). I didn't like it at all because the UI's rendering is so ugly on some devices and the user experience is broken. I had to use it with jQuery Mobile because it gave me a good UI design start. I tried some Phonegap Android generated applications on my personal device and it's really horrible. Some of them got rejected by Apple because of that ...
Second method is to use Appcelerator Titanium SDK. One word to sum it up: Awesome. One language to use (javascript) to create your UI/Controller. It's so easy to learn, so powerful to develop with and it has many out-of-the-box functionnalities (like facebook API, Yahoo Query Language, ...) that will allow you to put in place solutions easily for both Android and iPhone. BlackBerry is coming soon. What I liked the most is that it converts the written Javascript into the targetted platform with the default UI. It's really great. And, above all, the UI is easily customizable (with a css like system).
Personally, I put in place apps that can: Take a photo with the device then send it to a remote server, send messages to twitter/facebook, advanced geolocation, etc.
Third method: Native! It would take time if you target both iPhone and Android but, the big advantage is that you can create anything you want without being tied to a Framework for areas such as games, augmented reality , etc.
In my opinion, if you want to create simple applications with some nice features (weather, twitter feeds, sending on a facebook wall, ...), use Appcelerator Titanium SDK.
It converts your code into NATIVE.
If you have time to spend learning native languages, do it. It's the best way ;)
Hope it helps.
Regards.

I've summed up my thoughts on the whole "native vs. web" discussion in a blog post here: http://www.springenwerk.com/2011/09/thoughts-on-mobile-ui-design.html
In a nutshell: You can't get around getting to know the platform you are targeting if you want to provide a great user experience. Plus, you shouldn't try to mimic native UI/UX in a web application, it will only disappoint your users.

here are some pros and cons of native apps vs. web apps:
Native apps:
Native apps have more security
Native apps have higher user engagement, it has higher click-through rate (CTR) among the ad-serving publishers
When it comes to aesthetics and overall user experience, it is incredibly difficult for web apps to trump native apps
you don't have to buy a server and maintain it, therefore, for small businesses it is the ideal solution, not web apps which require a server.
Web apps:
it's cross platform - that means your one app will work on both iphone and android
cheaper and faster to develop and maintain
you will find programmers easier than native apps
updates are easier

Check out this post for some more opinion - http://www.thorntech.com/2013/01/html5-vs-native-apps-which-will-win-the-mobile-app-development-battle/
In particular, the last paragraph is worth noting. If you go down the path of building an HTML5 app, it is worth having some type of background "syncing" of content so you are not always pulling it from the web in real time. The app will be much more responsive if you load HTML pages from disk.

From my experience, the success rate of a native apps are much better than html or javascript based ones. I do not have sufficient numbers to back it up, but these are some issues that may crop up when trying to build html5 apps for different platforms. e.g.
Browser OS or webkit differences can cause unexpected bugs, css issues that could take quite a while to debug.
Your app is running on top of a webkit browser engine which takes up additional resources.
Older or non-smart phone devices may not have a modern webkit engine.
Nevertheless if you have good web skills over native, then getting an app to the market the quicket and cheapest route would be html5. Some apps lend very well for html5 such as data listing, and text content driven apps. I have written a writeup on HTML5 vs Native on my blog. Hope its useful.

iPhone native application vs web application

I am pretty new to iPhone and spent some months on it but.....But i think my learning went waste when i read about web application for iPhone...These can be developed even with a nil knowledge of Objective c...
I am very shocked about that what is need of an iPhone native app....i mean iPhone developers are less required now?
please suggest........

Well it's not that simple.
You can do quite a lot on the iphone with html5 and css3. Especially effects using webkit transforms are really impressive and performant. Furthermore, you can for example access the GPS hardware using javascript.
On top of that it is also possible to write 'enhanced' webapplications using a framework like phonegap (http://www.phonegap.com/) that enables you to use things like the accelerometer or tab controls via javascript as well as makes your webapplication into a compiled app that can be destributed via the appstore (and used offline).
Combine these features with a framework like sencha touch (http://www.sencha.com/products/touch/) or the currently developed jquery mobile and you can write really usefull applications that feel like native iphone apps using mostly just web technology. Another benefit is, that these applications can also be ported to android devices rather easily.
But this all comes at the price of performance. Thomas Fuchs blogged some of his experiences in speeding up web applications for the ipad here: http://mir.aculo.us/2010/06/04/making-an-ipad-html5-app-making-it-really-fast/
Generally speaking it is extremely hard to write realtime or image heavy applications that perform smoothly on the ipad and it is close to impossible to match the performance and smoothness of native core animation effects.
Furthermore things like file access, core data (some hacks exist) or direct access to the 3d hardware require you to write cocoa code anyway.
In my current applications i usually start with a bare-bone ios app containing some webviews. Then i sketch up features using web technology and implement performance critical parts using cocoa

I have no idea what you're talking about. Yes, there are two ways to develop applications that can run on the iPhone: web applications and native applications. Yes, web applications don't require you to know Objective-C. Yes, Objective-C is more difficult than HTML/CSS. But you can't do everything in a web application that you can in a native application. So no, native apps aren't going anywhere any time soon, and neither are the programmers who write them. They are no "less required" now than before.
It's the same thing on the desktop. You can write web applications that the user runs in their web browser, or you can write a native app in Objective-C. There is a place for both, but native apps aren't going anywhere any time soon.
You can choose to take the easier route, if you choose, but you won't end up in the same place as someone who has taken the time to learn Objective-C and written a native app. Whether you need that additional latitude and functionality is up to you. As long as you're making threats like "help me or I will leave this field", I suspect that very few of us will miss you.

A huge portion of possible apps that don't require the highest performance, special device hardware features not yet supported in HTML5, nor the security of compiled code, can be done as web apps.
But if you need the highest frame rates or a lot of number crunching, a native app can run from around 20X to over 200X faster than Javascript in a web app. A native app can also do audio processing and real-time video analysis, background VOIP or GPS tracking, use other brand new iOS APIs (MIDI keyboard support, etc.), and include lots of compiled libraries and other unix code that just isn't available in HTML5.

I've summed up my thoughts on the whole "native vs. web" discussion in a blog post here: http://www.springenwerk.com/2011/09/thoughts-on-mobile-ui-design.html
In a nutshell: You can't get around getting to know the platform you are targeting if you want to provide a great user experience. Plus, you shouldn't try to mimic native UI/UX in a web application, it will only disappoint your users.

What can be achieved in a native mobile application that can't be done in a HTML5 web app?

I've talked to a lot of people recently who say they are expecting to stop writing native mobile apps and start writing web apps once HTML5 gets more fully baked in mobile OSs. I just finished my first HTML5 deep dive, and I'm not yet convinced.
Will HTML5 work as a replacement development platform for native apps, or are there certain things that require targeting the native runtime?

HTML 5 is not magic. it adds a lot of long awaited functionality to HTML and to traditional web applications, but still - many things are still out of it's scope.
for example:
accessing your contact list
getting bluetooth data
making use of an OS specific function
for those (and other) functions - you would still need to write vendor specific applications.

One thing which necessitates the native app is the access to more features on particular mobile devices; it's not guaranteed that that all the features of the device is exposed via javascript interfaces to HTML5. In that case, you are forced to use whatever native APIs available.

In short, no. HTML5 provides an appropriate toolset for a large range of applications, so I see it growing popular in this arena (for portability reasons). I except there will always be application developers (and users) that prefer the native look and feel though, and there will always be scenarios in which bare-metal coding is required, or a 3D engine is more practical to utilize using system level API's.
HTML5 is a compelling technology stack though, especially when coupled with some cross-platform API management (e.g., PhoneGap).

Native applications will continue be able to use new device features first, before they are eventually supported up through to the browser so for cutting edge development, native will still be the way to go.
There is also an issue with discovery - right now users are accustomed to using apps and can find them in their devices app store. Searching for a web app seems unnatural to a typical user and that wont change any time soon. That's why a lot of apps that would seem to make more sense as a web app are still being produced as native apps.
Conclusion: Native apps will continue to be necessary, but mobile web app development will grow and may well replace more native app development as time goes on.

It will make some native apps unnecessary but not all of them. Not really much more to say about it :)

Creating a mobile version of a website

I'm looking to create a mobile version of our website/web app. What's a good way to provide the best, most fully featured version.
Part of the reason for creating it is instead of an iPhone app, so I'd like to offer an iPhone web app that takes full advantage of the iPhone's version of WebKit (so CSS animations, being able to rely on good javascript support etc). However, I'd also like the site to work well on other smart phones as well as more basic mobile phones as well.
Do I create two sites (Mobile WebKit and basic mobile web) and redirect based on User Agent? Can I create one site that degrades well? What are the possibilities, and how do other people handle it?
Also: are mobile web simulators worth a damn? I have an iPhone, so can test easily on that. If I want to test on Blackberry/Palm Pre do I really need a device or are there reliable simulators?

These are some of the iPhone specific libraries that provide a native look and feel on webkit:
iUi
jQTouch
Sencha Touch
iWebkit
Getting it to work on most phones will definitely be an issue with most libraries as they are built around with the iPhone's screen size (320x480) in mind.
To get a wider coverage of devices including Android and J2ME phones, checkout Yahoo Blueprint. It's a markup language that translates for various platforms and devices.
You could either get the mobile view based on User Agent by dynamically switching the stylesheet on your server when spitting the page. This is not a recommended approach though for heavy-duty pages as you will still be sending huge chunks of data that would not be rendered. Alternatively, if you have a clear separation of your views, you can templatize the view based on User Agent and/or other parameters. This has the advantage of keeping your controller logic in one place with only changing views. You could use the above libraries for iPhone/iPod Touch and switch to a simpler mobile version for other smartphones or tweak it as you want.
Creating a separate mobile version of the site can be painstakingly difficult to maintain when changes arise.
The iPhone and Android simulators are as close as it gets to the real deal. The iPhone won't let you do stuff like make calls on the simulator for obvious reasons, but the Android provides mock implementations for basically everything on the device.

Comparison between Corona, Phonegap, Titanium

Locked. This question and its answers are locked because the question is off-topic but has historical significance. It is not currently accepting new answers or interactions.
I am a web developer and I want to move my web products to iPhone. One of the products is like Google Maps: show map on the phone screen, you can drag or resize the map and view some information that we add to the map.
I know there are some technologies that enables you to use HTML, CSS and Javascript to develop native iPhone apps. I've identified a few:
Ansca Mobile
PhoneGap
Appcelerator
Are there other, similar products? What are the differences between them? Which should I choose?

I registered with stackoverflow just for the purpose of commenting on the mostly voted answer on top. The bad thing is stackoverflow does not allow new members to post comments. So I have to make this comment more look like an answer.
Rory Blyth's answer contains some valid points about the two javascript mobile frameworks. However, his key points are incorrect. The truth is that Titanium and PhoneGap are more similar than different. They both expose mobile phone functions through a set of javascript APIs, and the application's logic (html, css, javascript) runs inside a native WebView control.
PhoneGap is not just a native wrapper of a web app. Through the PhoneGap javascript APIs, the "web app" has access to the mobile phone functions such as Geolocation, Accelerometer Camera, Contacts, Database, File system, etc. Basically any function that the mobile phone SDK provides can be "bridged" to the javascript world. On the other hand, a normal web app that runs on the mobile web browser does not have access to most of these functions (security being the primary reason). Therefore, a PhoneGap app is more of a mobile app than a web app. You can certainly use PhoneGap to wrap a web app that does not use any PhoneGap APIs at all, but that is not what PhoneGap was created for.
Titanium does NOT compile your html, css or javascript code into "native bits". They are packaged as resources to the executable bundle, much like an embedded image file. When the application runs, these resources are loaded into a UIWebView control and run there (as javascript, not native bits, of course). There is no such thing as a javascript-to-native-code (or to-objective-c) compiler. This is done the same way in PhoneGap as well. From architectural standpoint, these two frameworks are very similar.
Now, are they any different? Yes. First, Titanium appears to be more feature rich than PhoneGap by bridging more mobile phone functions to javascript. Most noticeably, PhoneGap does not expose many (if any) native UI components to javascript. Titanium, on the other hand, has a comprehensive UI APIs that can be called in javascript to create and control all kinds of native UI controls. Utilizaing these UI APIs, a Titanium app can look more "native" than a PhoneGap app. Second, PhoneGap supports more mobile phone platforms than Titanium does. PhoneGap APIs are more generic and can be used on different platforms such as iPhone, Android, Blackberry, Symbian, etc. Titanium is primarily targeting iPhone and Android at least for now. Some of its APIs are platform specific (like the iPhone UI APIs). The use of these APIs will reduce the cross-platform capability of your application.
So, if your concern for your app is to make it more "native" looking, Titanium is a better choice. If you want to be able to "port" your app to another platform more easily, PhoneGap will be better.
Updated 8/13/2010:
Link to a Titanium employee's answer to Mickey's question.
Updated 12/04/2010:
I decided to give this post an annual review to keep its information current. Many things have changes in a year that made some of the information in the initial post outdated.
The biggest change came from Titanium. Earlier this year, Appcelerator released Titanium 1.0, which departed drastically from its previous versions from the architectural standpoint. In 1.0, the UIWebView control is no longer in use. Instead, you call Titanium APIs for any UI functions. This change means a couple things:
Your app UI becomes completely native. There is no more web UI in your app since the native Titanium APIs take over control of all your UI needs. Titanium deserves a lot of credit by pioneering on the "Cross-Platform Native UI" frontier. It gives programmers who prefer the look and feel of native UI but dislike the official programming language an alternative.
You won't be able to use HTML or CSS in your app, as the web view is gone. (Note: you can still create web view in Titanium. But there are few Titanium features that you can take advantage of in the web view.)Titanium Q&A: What happened to HTML & CSS?
You won't be able to use popular JS libraries such as JQuery that assume the existence of an DOM object. You continue to use JavaScript as your coding language. But that is pretty much the only web technology you can utilize if you come to Titanium 1.0 as a web programmer.
Titanium video: What is new in Titanium 1.0.
Now, does Titanium 1.0 compile your JavaScript into "native bits"? No. Appcelerator finally came clean on this issue with this developer blog:Titanium Guides Project: JS Environment. We programmers are more genuine people than those in the Marketing department, aren't we? :-)
Move on to PhoneGap. There are not many new things to say about PhoneGap. My perception is that PhoneGap development was not very active until IBM jumped on board later this year. Some people even argued that IBM is contributing more code to PhoneGap than Nitobi is. That being true or not, it is good to know that PhoneGap is being active developed.
PhoneGap continues to base itself on web technologies, namely HTML, CSS and JavaScript. It does not look like PhoneGap has any plan to bridge native UI features to JavaScript as Titanium is doing. While Web UI still lags behind native UI on performance and native look and feel, such gap is being rapidly closed. There are two trends in web technologies that ensure bright feature to mobile web UI in terms of performance:
JavaScript engine moving from an interpreter to a virtual machine. JavaScript is JIT compiled into native code for faster execution. Safari JS engine: SquirrelFish Extreme
Web page rendering moving from relying on CPU to using GPU acceleration. Graphic intensive tasks such as page transition and 3D animation become a lot smoother with the help of hardware acceleration. GPU Accelerated Compositing in Chrome
Such improvements that are originated from desktop browsers are being delivered to mobile browsers quickly. In fact, since iOS 3.2 and Android 2.0, the mobile web view control has become much more performing and HTML5 friendly. The future of mobile web is so promising that it has attracted a big kid to town: JQuery has recently announced its mobile web framework. With JQuery Mobile providing UI gadgets, and PhoneGap providing phone features, they two combined creates a perfect mobile web platform in my opinion.
I should also mention Sencha Touch as another mobile web UI gadget framework. Sencha Touch version 1.0 was recently released under a dual licensing model that includes GPLv3. Sencha Touch works well with PhoneGap just as JQuery Mobile does.
If you are a GWT programmer(like me), you may want to check out GWT Mobile, an open source project for creating mobile web apps with GWT. It includes a PhoneGap GWT wrapper that enables the use of PhoneGap in GWT.

From what I've gathered, here are some differences between the two:
PhoneGap basically generates native wrappers for what are still web apps. It spits out a WhateverYourPlatformIs project, you build it, and deploy. If we're talking about the iPhone (which is where I spend my time), it doesn't seem much different from creating a web app launcher (a shortcut that gets its own Springboard icon, so you can launch it like (like) a native app). The "app" itself is still html/js/etc., and runs inside a hosted browser control. What PhoneGap provides beyond that is a bridge between JavaScript and native device APIs. So, you write JavaScript against PhoneGap APIs, and PhoneGap then makes the appropriate corresponding native call. In that respect, it is different from deploying a plain old web app.
Titanium source gets compiled down to native bits. That is, your html/js/etc. aren't simply attached to a project and then hosted inside a web browser control - they're turned into native apps. That means, for example, that your app's interface will be composed of native UI components. There are ways of getting native look-and-feel without having a native app, but... well... what a nightmare that usually turns out to be.
The two are similar in that you write all your stuff using typical web technologies (html/js/css/blah blah blah), and that you get access to native functionality through custom JavaScript APIs.
But, again, PhoneGap apps (PhonGapps? I don't know... is that a stupid name? It's easier to say - I know that much) start their lives as web apps and end their lives as web apps. On the iPhone, your html/js/etc. is just executed inside a UIWebView control, and the PhoneGap JavaScript APIs your js calls are routed to native APIs.
Titanium apps become native apps - they're just developed using web dev tech.
What does this actually mean?
A Titanium app will look like a "real" app because, ultimately, it is a "real" app.
A PhoneGap app will look like a web app being hosted in a browser control because, ultimately, it is a web app being hosted in a browser control.
Which is right for you?
If you want to write native apps using web dev skills, Titanium is your best bet.
If you want to write an app using web dev skills that you could realistically deploy to multiple platforms (iPhone, Android, Blackberry, and whatever else they decide to include), and if you want access to a subset of native platform features (GPS, accelerometer, etc.) through a unified JavaScript API, PhoneGap is probably what you want.
You might be asking: Why would I want to write a PhoneGapp (I've decided to use the name) rather than a web app that's hosted on the web? Can't I still access some native device features that way, but also have the convenience of true web deployment rather than forcing the user to download my "native" app and install it?
The answer is: Because you can submit your PhoneGapp to the App Store and charge for it. You also get that launcher icon, which makes it harder for the user to forget about your app (I'm far more likely to forget about a bookmark than an app icon).
You could certainly charge for access to your web-hosted web app, but how many people are really going to go through the process to do that? With the App Store, I pick an app, tap the "Buy" button, enter a password, and I'm done. It installs. Seconds later, I'm using it. If I had to use someone else's one-off mobile web transaction interface, which likely means having to tap out my name, address, phone number, CC number, and other things I don't want to tap out, I almost certainly wouldn't go through with it. Also, I trust Apple - I'm confident Steve Jobs isn't going to log my info and then charge a bunch of naughty magazine subscriptions to my CC for kicks.
Anyway, except for the fact that web dev tech is involved, PhoneGap and Titanium are very different - to the point of being only superficially comparable.
I hate web apps, by the by, and if you read iTunes App Store reviews, users are pretty good at spotting them. I won't name any names, but I have a couple "apps" on my phone that look and run like garbage, and it's because they're web apps that are hosted inside UIWebView instances. If I wanted to use a web app, I'd open Safari and, you know, navigate to one. I bought an iPhone because I want things that are iPhone-y. I have no problem using, say, a snazzy Google web app inside Safari, but I'd feel cheated if Google just snuck a bookmark onto Springboard by presenting a web app as a native one.
Have to go now. My girlfriend has that could-you-please-stop-using-that-computer-for-three-seconds look on her face.

I'm taking a course in Android/iPhone development and we spent 8 weeks with Titanium (not full time) (Version was Titanium 1.4.2 and time was around November 2010). Here is my experience.
iPhone Android dual targetting
Even though the API guides claim that the functionality is available for both the Android and iPhone, this is not the case. Much of the stuff simply don't work on one of the platforms. Some things works differently.
A lot of the people in the class has done iPhone applications, and they can not make them work on Android without major rewrites. I developed a simple childrens app called Animap (see android market / Appstore in Sweden) and started developing under Windows. Once the Android target was working I opened the project on OS X. It does not show any build stuff for iPhone, just for Android. You need to start a dual target project under OS X. (Ok, I copied the relevant files to a new project). Next problem - the animations does not work on iPhone (they work on Android). The scrolling events does not work the same on the iPhone. (i.e on Android you get the untouch event when user stops scrolling and releases their finger from the screen, this does not happen on the iPhone).
Since this is not mentioned somewhere you basicly need to do trial and error programming on first one platform, then on the other platform. By trial and error I mean it will take about two days to get such a simple App as Animap working on the other platform. You will also need to have if (android) then... or if(iphone)... all over your code...
Download and setup
You must follow the instructions to the letter.
Do not try to use java 64 bit. It will not compile the KitchenSink 1.4.0 demo application. (1.3 works OK!)
You must put files directly on the C drive as long pathnames will make the external program not receiving all command line parameters if they get to long. (Fine for small programs though)
1/3 of the times, the toolchain simply stops and you must press 'launch' again. Then it will probably work... very unreliable.
The simulator will not be found on startup and then you must simply kill of adb.exe with Ctrl+Alt+Delete and retry.
Network connection
On a wifi-network you sometimes looses the live connection and Titanium crashes on you (the compile/deploy interface)
If you do not have a working internet connection it will not start as it can not log you in to their servers.
API
CSS, HTML and jQuery is a breeze compared to this. Titanium resembles any other old GUI API, and you need to set some properties for every single button/field/etc. Getting a field wrong is just to easy, remembering all the properties that needs to be set? Did you spell it with capital letters at the right place? (as this is not caught by the compiler, but will be seen as a runtime error if you are lucky to test that part)
In Titanium things simply break when you add another view on top of a control or click somewhere else in the GUI.
Documentation
Several API pages carry the Android symbol, but will only return a null when you try to create the control. They are not simply available on the Android platform despite the symbols. Sometimes Android is mention to not support a particular method, but then the whole API is missing.
KitchenSink
The demo application. Did I mention it does not compile if you put it in your Eclipse project folder because the path gets too long? Must be put on your C drive in the root folder. I currently use a symbolik link (mklink /J ...)
Undocumented methods
You must propably use things as label.setText('Hello World') to change a label reliable but this is not documented at all.
Debugging
Titanium.API.info('Printouts are the only way to debug');
Editing
The APIs are not available in any good format so you can not get ordinary code-completion with help etc. in Eclipse. Aptana please help out!
Hardware
It seems that the compiler/tools are not multithreaded so a fast computer with a fast harddrive is a must, as you must do a lot of trial & error. Did I mention the poor documentation? You must try out everything there as you can't trust it!
Some positive things
Open Source
From previous projects I have promised myself never ever to use closed source again as you can't simply fix things just by throwing hours and manpower at it. Important when you are late in the project and need to deliver for a hard deadline. This is open source and I have been able to see why the tool chain breaks and actually fix it as well.
Bugdatabase
It's also open. You can simply see that your not alone and do a workaround instead of another 4 hours spent on trial&error.
Community
Seems to be active on their forums.
Bugs
Titanium 1.4 is not threadsafe. That means if you make use of threads (use the url: property in a createWindow call) and program like the threads are working and send events with data back and forth you run into a lot of very, very strange stuff - lost handlers, lost windows, too many events, too few events, etc. etc. This is all dependent on the timing, putting the rows of code in different order might crash or heal your application. Adding a window in another file.js breaks your app.js execution... This also trashes internal datastructures in Titanium, as they sometimes can update internal datastructures in paralell, overwriting a just changed value with something else.
Much of the problems I have had with Titanium comes from my background on realtime systems like OSE who support hundreds of threads, events and message passing. This is supposed to work in Titanium 1.4 but it simply doesn't do it reliably.
Javascript (which is new to me) dies silently on runtime errors. This also means that small and common bugs, like misspelling a variable name or reading in a null-pointer does not crash when it should so you can debug it. Instead parts of your program just stop working, for instance an eventhandler, because you misplaced/misstyped a character.
Then we have more simple bugs in Titanium, like some parameters not working in the functions (which is quite common on the Android platform at least).
Trial and Error debug cycle speed
Having run Titnium Developer on several computers, I noticed that the bottleneck is the harddrive. An SSD drive on a laptop makes the build cycle about 3-5 times faster than on a 4200 rpm drive. On a desktop, having dual drives in RAID 1 (striping mode) makes the build about 25 percent faster than on a single drive with a somewhat faster CPU and it also beats the SSD drive laptop.
Summary
From the comments in this thread there seems to be a fight for the number of platforms a tool like this can deliver app's for. The number of API seems to be the key selling-point.
This shines through very much when you start using it. If you look at the open bugtracker you see that the number of bugs keeps increasing faster than the number of fixed bugs. This is usually a sign that the developers keep adding more functionality, rather than concentrating on getting the number of bugs down.
As a consultant trying to deliver rather simple apps to multiplatforms for a customer - I'm not sure this is actually faster than doing native app development on two platforms. This is due to the fact that when you are up to speed you are fast with Titanium, but then suddenly you look down and find yourself in a hole so deep you don't know how many hours must be spent for a workaround. You can simply NOT promise a certain functionality for a certain deadline/time/cost.
About myself: Been using Python for two years with wxPython. (that GUI is inconsitent, but never breaks like this. It might be me that have not understood the threading model used by Javascript and Titanium, but I am not alone according to their open discussion forums, GUI objects are suddenly using the wrong context/not updating..???) before that I have a background in C and ASM programming for mobile devices.
[edit - added part with bugs and not being thread safe]
[Edit - now having worked with it for a month+, mostly on PC but some on OS X as well. Added iPhone and Android dual targetting. Added Trial and Error debug cycle speed.]

The Corona SDK (Ansca Mobile) uses Lua as its coding language. See lua.org for more about Lua.
While we plan to add further web integration and native-UI elements, our focus will tend to be on graphics-intensive applications, such as game development, as opposed to web-based technologies. In other words, we don't envision people writing Corona apps entirely in Javascript/HTML/CSS.

I have been working with Titanium for over a week now and feel like I have a good feel about its weakness.
1) If you hoping you use the same code on multiple platforms good luck! You'll see something like backgroundGradient and be amazed until you find out android version doesn't support it. Then have to revert to using a gradient image, might as well use it for both versions to make the code easier right?
2) A lot of weird behaviors, on the Titanium android sdk you need to understand what a "heavy" window is just to get the back button to work, or even better orientation event tracking. This isn't how the android platform really is, its just how Titanium tries to make their API work.
3) Your thrown in the dark, Things will crash and you have to start to comment code and then when you find it, never use it. There are certain obvious bugs, like orientation and percents on android that have been a problem for over six months.
4) Bugs .... there are a lot of bugs and they will be reported, sit around for months, get fixed in a few days. I am surprised they even are planning to release a black berry mobile sdk when there are so many other problems with android.
5) Titanium Iphone versus Titanium Android javascript engines are completely different. On android version you can download remote javascript files, include and use libraries like mootools, jquery and so on. I was in heaven when I found this out because I didn't have to keep compiling my android app. The android apk installation process takes so long! Iphone none of that is possible, also the iphone version has a much faster javascript engine.
If you stay away from a lot of the native UI parts, i.e instead use setInterval to detect orientation changes, sticking with gradient images, forget about the back button, build your own animations, forget window header, toolbars, and dashboard. You really can make an api that works on both that doesn't require of lot of rewriting. But at that points its just as sluggish as a webapp.
So is it worth it? After all the pain, its worth every minute. You can abstract the logic and just build different UI for each rather then if elseing everywhere. Titanium lets you make fluid applications, that feel fast. You lose the powerful layout abilities of each platform but if you think simple, things can get done under a single language.
Why not a web app? On entry level market android phones its horribly slow to generate a webview and consumes a lot of memory you could be using to do more complex logic.

Here's a more recent and in depth analysis of Appcelerator and PhoneGap: http://savagelook.com/blog/portfolio/a-deeper-look-at-appcelerator-and-phonegap
And here's even more detail on how they differ programmatically:
http://savagelook.com/blog/portfolio/phonegap-is-web-based-appcelerator-is-pure-javascript

native mapkit is supported in Titanium

Making HTML5 widgets tha look like iphone widgets is one thing, but making them perform equally well is another matter altogether. Performance of html5 animations (even plain View Transitions), scrolling long lists, responsiveness to gestures feel sticky and jerky. An iPhone user will notice the difference.
There's also some differences in the kinds of gestures that are supported by different devices which results in platform specific code and usability issues as well.
I'll stay with native apps for now I guess.

Rhomobile Rhodes (http://rhomobile.com/products/rhodes) is very similar in approach to PhoneGap, but is the only framework with:
a Model View Controller pattern (as
most web frameworks provide)
an Object Relational Manager
support for all popular smartphones (including Windows Phone 7)
a hosted development service (not just hosted build): http://rhohub.com
a full debugger and SDK-less emulator in the RhoStudio IDE
support for synchronized offline data

For anybody interested in Titanium i must say that they don't have a very good documentation some classes, properties, methods are missing. But a lot is "documented" in their sample app the KitchenSink so it is not THAT bad.

My understanding of PhoneGap is that they provide Javascript APIs to much of the iPhone APIs.
Titanium seems easier for a web developer background. It is a simple XML file to create a basic TabView application and then everything in the content area is controlled by HTML / JS. I also know that Titanium does provide some javascript access to some of the frameworks (particularly access to location information, the phone ID, etc).
UPDATE: Titanium added Maps API in version 0.8 of their framework.

You should learn objective c and program native apps. Do not rely on these things you think will make life easier. Apple has made sure the easiest way is using their native tools and language. For your 100 lines of javascript I can do the same in 3 lines of code or no code at all depending on the element. Watch some tutorials - if you understand javascript then objective c is not hard. Workarounds are miserable and apple can pull the plug on you anytime they want.

Of the solutions you mentioned, none of them appear to give you direct access to the MapKit framework introduced in OS 3.0.
As the Google Maps HTML widgets aren't nearly as good as MapKit (see Google Latitude for an example), you are probably best off developing a native Cocoa touch application, or choosing a solution you can extend to add MapKit integration. PhoneGap is extensible in this manner (it's open-source so it is by default), and some of the other solutions might be as well.
edit: Titanium now has support for MapKit

I've tried corona. It was good until I discovered it doesn't support streaming mp3 audio.
So, I stopped right there. I think if I really want to be an iphone app developer I should learn obj c. All I wanted to make an app which has a list of radio stations and you click on them it start playing.