One of the reasons I may have been accepted to Sonic Retro was my disassembly of Sonic Advnace on Android. Some of you may remember that version was released only in Japan in 2011.
If GBA rom hacking was hard, hacking the Android Version should be easier! All you need to know is how to make an Android app. To make a mod, you'll need an Android app editoor.
You can download the disassembly here.
I hope to see many great mods for the Android version, and hope to see the ULTIMATE mod in next years SHC!!!