NOTE: THIS APP NEEDS ROOT, BECAUSE USES CONSOLE COMMANDS FOR SIMULATE KEYPRESS!
First youll have to sync your pc with your android device.
then open PCBTKeyboard.jar, and press on "Start bluetooth connection" button
Then open android app, and search on paired list (or press scan devices), your pc, and connect It.
Finally, write on your pc, and it will be written on your phone
Some screenshots (pc and phone):