I'm a new student of the Tom Hess corporation and am in my second month of their correspondence lesson program. It's very expensive, but I believe that I can learn from it. I did use their "Practice Generator" and "Accelerometer" apps and I think that these might be okay for people that learn a certain way, but THE COST for these two simple apps is simply appalling. I paid about $80 CDN for a one month 'subscription' to them. The "Practice Generator" is a stopwatch/Timer that's connected to a list of practice activities and the "Accelerometer" is a metronome that lets you track your playing speed and progress. If I had paid $5 to own each of these apps I would have been disappointed, but I actually paid about $80 CDN for one month's access to them.