Android Question how to write a keyboard app?

[hears]

is it possible in B4A ?I try write a russian input keyboard , for example,when i use facebook ,i can use this app input russian.
before i have write app with russian keyboard.but this keyboard only can use in myself app.

 

[Erel]

You will need to implement an InputMethodService: https://developer.android.com/guide/topics/text/creating-input-method

I don't think that it was implemented in any of the currently available libraries.