Are there any frameworks or projects that support cross-platform mobile game development? At the moment Titanium does cross platform development, but doesn't support high end graphics APIs, so many things still have to be written specifically for a given platform.
Unity is probably your best bet, it supports both iOS and Android, as well as Windows and Mac.
The main advantage is that you can code and test by making a browser accessible webpage and navigating to it from the mobile device. Additionally the platform specific differences are very limited, though still present.
PhoneGap can also assist in creating "native" apps from cross platform web apps.
There are a ton of options for this, so it really depends on your budget and long term hopes. If you're planning on just making a one-off, then something like MonoTouch, Flash and Unity would be perfectly fine. If you want this code to be something you can grow and own yourself, then writing your own C++ layer that works with OpenGL on both platforms would be the best way to go.
Airplay SDK uses C++ and works across different mobile platforms (Android, iPhone, Symbian, etc)
As noted above Unity is a solid choice, it supports Mac and Windows machines (desktop and web), iOS and Android devices as well as all three consoles (PS3, Wii, X360, downloadable and retail titles).
Mono supports iphone (mono touch) and android (mono droid) I am not sure how well game development would be supported through either of those. You would also be able to support WP7 as well. Sure the platform interface code would be different but you should be able to use 80- 90% of your code on all three platforms.
I have bad experinace in choosing Cross platform game development SDK, I did research and evaluated many SDK, and I finalized to use Airplay SDK, seems SDK has good documents and samples, so easy to jump, I developed around 60 games which deployed on android and iphone, it works fine.
Now I would like to integrate ad on Airplay based games, and seems airplay don't have capability to render HTML,CSS & JS (like webview), Seems it allow only to draw image but don't have HTML.
So if you are thinking to develop games without ads(or if you have own image ads) then I think Airplay is fine, if you are thinking to have ad, then I suggest to not go with Airplay.
Shiva 3D does iPhone, Android, WebOS and Airplay. It also has many non-mobile options.
I'm an indie game mobile game developer and there is not a week that goes by without me trying to find a better toolset.
You can have a look at:
- Shiva 3D / Marmelade
- Flash (current game is using Flash Mobile)
I don't think HTML5 is there yet for cross platform... maybe one day. I have the additional requirements that my games must work on the Blackberry as well...
On the other hand, you may also want to look at Skiller SDK, it provides multi-platform support (Android, J2ME, Symbian and iOS in the works). It's a third-party SDK which augments gaming capabilities on multiple native platforms.
Unity and Sio2 look really solid and impressive. Pricey yes but I understand how much it is challenging to create such products.
You can check out Adobe AIR, which lets you write-once-run-anywhere in Flash and Actionscript for platforms like desktop, iOS and Android. It requires a bit more optimisation skill to optimise for mobile platforms, but once that's done deploying to either iOS or Android shouldn't be a problem.
See http://corlan.org/2011/07/18/using-adobe-air-to-reach-multiple-devices-conqu/ for an example of reaching multiple platforms using 1 code base.