It's a cool app and must have taken a lot of work. As a piano teacher myself: teaching chords is important but showing those notes on a staff I would think would be even more important. And showing chords in a grid with no relation to any other instrument doesn't really do anything pedagogically. If the chords were in their places on the keys of a piano or at least the colors of the keys, where flats and sharps were black and natural keys were white. Wave forms are cool but don't really teach anything (if you really are going for education here and not just a cool app).