The GO:PIANO88 (GO-88PX) is compatible with the Roland Piano App (free, iOS/Android).
The app lets you view sheet music, practice songs interactively, play along with rhythms, and track your practice sessions.
Note: The Accompaniment section of the Roland Piano App is not available for the GO-88PX.
For connection instructions, see the "Connecting the GO:PIANO88 to a mobile device via Bluetooth®" section in the GO:PIANO88 (GO-88PX) Reference Manual.