I've just got The Beatles Little Black Songbook for my iPhone which has lyrics and chords to over 160 Beatles songs.
It has the backing tracks so you can play along which is cool.
It also has a few video lessons to help you the learn songs, one of which is And Your Bird Can Sing which I've always wanted to play, (did George play the lead guitar or Paul?). Anyway I can play it now!
According to the app its all official etc.