For update version (Every week) visit
https://www.aparajeyo.com/software/on-screen-bangla-keyboard/
Download Keyboard Layout Creator For Free :
https://www.aparajeyo.com/software/keyboard-layout-creator/
On Screen বাংলা Keyboard
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Provat
Unijoy
National (BD)
SMT (All layouts)
Soumili
Lipikaar
and many many more keyboard layouts !