Overriding Android Native Keyboard

I programmed a customKeyboard. What I need to do is to override native softkeybaord, system wide. Is it possible to do so? If yes, how can it achieve this and if no, then what are

Solution 1:

It's called an "Input Method Editor"

There are plenty of apps such as swiftkey and swype which are custom keyboards which work this way. Basically, Android let's the user choose who will manager their input (both keyboard and touch).

Solution 2:

After installing your keyboard (apk), the user has to enable it manually in Settings -> Language & Input -> Default Keybaord. As pointed out by @hatcyl, there are plenty of other apps out there taking the same approach.