It was actually pretty easy for Android software to change to support full-screen touch UI. Just add a software keyboard and inertial scrolling and enlarge the

It was actually pretty easy for Android software to change to support full-screen touch UI. Just add a software keyboard and inertial scrolling and enlarge the button sizes. You can verify this by reading the AOSP sources to see how little code was added/changed. Android was lucky to have an internal software architecture that was easy to reskin to support iPhone style UI. All the alternatives had more work to do.