Long story short: How open is Android OS for developers?
A little in depth:
For instance, if I’m willing to write my own text-input interface, would it be possible (like, totally overwrite the built-in-phone one)? Or that’s something like core feature and cannot be changed?
And, is there a difference for developers, whether I buy a Google phone, HTC or Samsung etc.?
P.S. If that’s all possible, no warranty voids for such changes?
Hope I’ve made myself clear and thanks in advance!
You can create custom input method. For development the best is Google phone, but in order to work on all hardware, especially a keyboard, you need to test on all the devices you want to be supported (try to borrow them instead of buying all of them :P)