You can compile Qt Applications for Android with the Necessitas Framework (
http://sourceforge.net/p/necessitas/home/necessitas/), BUT:
a) As far as I know the score visualization in PB is done with OpenGL. Android supports only OpenGL ES, so this part has to be rewritten.
b) the connection between piano and android is painful since there is no smartphone which has a serial port. So you have to use a special "MIDI to USB(-Host)" or "MIDI to Bluetooth" converter.
Greetings
Konstantin