Im looking into writing a fairly simple iPhone app and need some advice on the choice of platform. I have the following constraints:
App Requirements:
The app should be able to receive strings via a wifi network, process these and then display either a message, or show a preset photo from the library, or change the background color (or any combination of these).
Once started the app will be running continuously on the device, and be a display only client (ie no user interaction on the device itself) - just processing instructions as received over wifi.
Speed: once the strings are sent to the device, the app has to respond quickly (either display image, change color or show preset text as soon as possible.)
My Current Situation:
No previous iOS development experience.
I need to do this within the next 2 months.
I am very comfortable with: HTML, JS, CSS, Python & PHP.
I am familiar with other languages e.g. C++ but have not touched these in a long while.
Question: Choice of Platform:
I know that the best choice would be to use the native iPhone SDK, but given my time constraints and knowledge of existing tech, could tools such as Appcelerator Titanium or PhoneGap be proficient for this kind of application?
Note: At this stage I do not foresee the app being listed on the app store, its meant for personal use only, although this may change in the future.
If it would be an option to load the images from a remote server instead of the local photo library and you being already familiar with HTML/JS/CSS/PHP, why not just make an Web-App that is running full-screen?
You can use your existing knowledge and you're saving money (no $99 license fee)
You might want to try TapLynx - it's possible to create a native app without any code.
I think you can do everything you want to do with Titanium. It even supports Sockets should you need to go to that raw of a level. Native iOS development is painful and hideous.
Appcelerator is glorious and fun :]
I want to start developing IPhone application.
I need to understand something about it - I am working with a graphic designer.
If she supplies the GUI in HTML - will it be easy for me to develop with it?
How does it work? like regular web development?
Apple uses Objective C and Cocoa for iPhone applications. Neither uses HTML; you'll instead be using interactive controls like you'd find in a desktop application. Whether it's easy for you to develop using an HTML mockup will depend entirely on your skills with Cocoa. (In the same way I encourage designers to give me mockups in Photoshop knowing that I can easily build HTML versions of them.)
You might want to start with some of Apple's documentation on iPhone development: http://developer.apple.com/devcenter/ios/index.action
For GUI development of your own apps you have several options:
Code: UIKit framework in Objective-C
Interface Builder: Tool to click
your GUI together, but the logic
will be coded like in 1 in C, Obj-C
or C++
You can build a HTML gui and
present it in a web view, but for
native apps, this will only bring
you so far.
Oh, and no native Flash on iOS. :-)
You could write an app that uses HTML for its UI - in essence you'd simply be wrapping a webkit widget and driving your app from events generated by that UI. However, that's not going to give you a UI that really takes advantage of the phone.
For that, you need to get down and dirty with Objective C and the Cocoa Touch API for iOS. Another option is using Flash CS5, which is ActionScript based.
Strictly speaking, the answer is no, your HTML skills are not transferrable.
That said, there are two projects that deserve looking into, both of which are about producing native (or "native-ish") apps from HTML and JavaScript. The first is PhoneGap, and the second (which I think is more robust and promising) is called Appcellerator.
Neither of them give you really-and-truly full access to to the iPhone API, but they do allow a significant flattening of the learning curve for people who already have well developed web app skillz.
If you go the native route, bear this in mind: it took me about a month to go from being a web developer to being a slightly competent iOS developer, and six months or so to feel solid and reliable and productive with iOS.
develop android apps that should support iphone,ipad,android.is there any way for developing this kind of generic app or we need to develop aps depending on mobile os
Though it is possible to create an universal application for iphone and ipad i don't think you can do the same for Android.
In my opinion it is always better to port your application to Android based on your requirements so that you can take advantages of the API's that the platform is offering you.
You can try using a framework named Titanium Appcelrator. This framework will help you target iPhone, iPad, Android with the same code base. This also lets you access most of the Native hardware features available with these platforms but not all. It seems that this also may support Blackberry soon.
We are struggling with the same question at the moment. Since we are working for Android, Maemo, Meego, iPhone and Blackberry (+Symbian 3 soon), HTML5 looked promising, and we dedicated quite some time investigating it. The end result was HTML5 is not yet ready for the development we were hoping for. It's fine if you need simple functionality, but as soon as something more advanced is needed, you need to create a different version. Even if it suits your needs, every platform requires different HTML5-to-native bridge, and every platform has a different engine. As you can see, only front end part could be partially used.
In your case, you need two different applications, one for Android, another one for iPhone/iPad. Try to see if you could take advantage of HTML5, if not, you are unfortunately stuck with separate development for some time to come. Unless you will create a web app and use it with device's browser.
You can create common functionality libraries with C or C++ and use these libraries in iPhone/iPad and use Android's NDK tool to integrate theses libraries with Android
On Android, you're using Java as the main language, and you can also use C and C++ . On iOS, you're using Objective-C as the main language, and also can use C and C++. So the common denominator would be C (at least on the iPhone there are no C++ GUI classes). I have no idea about developing on Android, but on iPhone it's no fun to purely work in C (and I'm not sure if it's even possible, maybe it is but should I when working with Objective-C/Cocoa is fun).
What you can do is write generic logic and share that between both systems, like a library. For example, I worked on a project where we used a C++ SIP/VoIP library that also compiles and runs on Symbian. It shouldn't be a big problem to write C code that can be shared between iOS and Android, as long as it is mostly about logic and not about calling system-specific stuff (you can of course include system specific stuff and guard that with #ifdef but you don't want your library to have more system-specific than system-agnostic code, I guess). For example, if you intend to write a networked game you could implement the network protocol in a way that could be shared between iOS and Android.
But as soon as you're hitting the GUI level I don't think you can share any code, and even if you could you probably don't want to because if you use the native languages/IDEs you are faster designing the GUIs each in their respective main languages/IDEs than trying to find a common way and then have to live with compromises and trying to make it work on both systems all day long. Better to implement the GUI native to each platform (e.g. Xcode has a very good graphical tool called Interface Builder that can save a lot of work/typing).
we can go for the XML VM to run the android apps in iphone.
Check this for more info.
xmlvm.org
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.