I have enjoyed the challenge of relearning mathematics with Math Academy as well. I find the format and reviews extremely helpful- it is so refreshing to end a lesson or review early if you are getting all the answers right compared to the drudgery of my schooling experience where you are getting question after question that isn't introducing a new mental challenge.

My only desire is that their site worked on my phone- it would be nice to do a lesson when I have some free time and some paper.