Fantastic all around and great support!

Wasnt sure if the MIDI functionality would work well on an iPhone. Emailed support, they responded very quickly with an answer, and then proactively followed up with further details to help ensure it would work for me (turns out out be easy - just like the iPad). Ive been using this all night tonight and this app is exactly what Ive been looking for! Its so easy to just open the app, plug my iPhone into my keyboard, and play/practice. And, of course, I can practice anywhere on just the iPhone when I want. All functionality listed in the App Store description works great! I highly recommend!

Allanon Lee about Piano Tutor App, v7.1