Like others have said, it's doable, but difficult.
The other issue that you will run into if you were to do this is that you'll probably get poor performance. iPhones don't have very impressive internals. I think the 4s only has 512 MB of RAM and a pretty slow processor compared to high end Android phones. (Apple doesn't officially release those kinds of specs.) iPhones perform well because the OS and the apps are all optomized to work well with the hardware, even though the hardware isn't very fast. (Since you only have one set of hardware, you can build everything custom for it.)
If you want to do this for the "project" aspect of it, that's fine; have fun. But if this phone is going to be your daily driver, you'll probably be disappointed, especially when you consider how much money you'll spend on the iPhone vs the poor quality of the user experience you'll end up with.
The 4S has respectable specs. Dual core based on Samsung Exynos, but with a better GPU.
1gb of ram.
Not a spec slouch. The new ipad has pretty awesome specs, too.
Sent from my HTC One X using Android Central Forums
Hello all,
ok, if you want to do this for the "project" aspect of it, that's fine; have fun. But if this phone is going to be your daily driver, you'll probably be disappointed, especially when you consider how much money you'll spend on the iPhone vs the poor quality of the user experience you'll end up with.
Its possible, but not worth it. If you want ics or any cm build, just buy an android phone. Good luck!