I played around with this a bit on my iPad. The only score I could work with is "Scales"! It checks for note accuracy, duration, evenness, tempo, etc., which seems to work pretty well. The one thing I'm not sure about or didn't see is the ability to start from a particular spot in a score. I think that would be very important, I wouldn't want to start from the beginning each time. Also, how does it deal with rubato? Playing things metronome like isn't good either.
You can purchase additional scores inside the app. Most seem to be beginner pieces, but there are some more advanced pieces.
