Surprisingly good
I was a bit skeptical of this app but its actually quite good!!
There is a lot of variety in the exercises and its fun to have a way to keep track of what you have done this way.
Of course you can cheat and trick the app into thinking you are exercising when you are not, but if you do that, you are missing the point.
There is a bit of "engrish" scattered through the text of the app and I had difficulties setting my height properly (glitch with setting the feet measurement) but even with those minor things, this is worth checking out.
Blakepro about
Fit for Rhythm Groove! Aerobics