This app is WONDERFUL. I teach class piano at a magnet music middle school, and I bought this for our lab. It's easy to use and the kids love it. I really like the reports feature, as my students can screenshot the report and upload to Edmodo. There are very few software options for teaching music theory, and even fewer that utilize MIDI keyboard. Really glad I found this.
Yes, it does need better instructions, but it's fairly straightforward. Just choose the topic and practice. Also, the developer is really cool. I just emailed support and he wrote me back in like 5 minutes.
I like it. I got it with basic reading and so I'm learning to read notes and make cords together. Highly recommend.