Yousician
We understand that learning the piano isn't always enjoyable, especially if you're attempting to push yourself or a less motivated pupil. Yousician is unique in that it makes learning fun by allowing you to earn stars and awards for playing every day. It also works as a modest challenge by requiring you to acquire new tiers of classes and content.
Apart from that, there's a lot to like here. Everything is bright and clearly described, and the interface is tidy and easy to use. The choice of tunes accessible to play is pleasingly large. Because of the game-like approach, you don't receive the whole experience of learning notation right away, and this only opens up at 'level three,' we believe that alternative programs, while less exciting, provide a better foundation from the start.
It works perfectly on most platforms, however we did notice significant delay on the Apple version, which can completely throw off your timing and spoil your experience. Overall, though, it's fantastic.