It was a pretty good app up until the point where, during the reading sections where they want you to spell out the romaji, I was spelling it out perfectly to match the Katakana and yet was getting told my answer was wrong. I ended up looking some of these words up, and realized it was actually the app that was wrong. If those things were to be fixed, it could be very helpful, but unfortunately once you get to a certain point you just hit a wall due to the fact that the answers don’t match up with the drills properly.