Yeah I am in the final stages of bug hunting on mobile devices, so far its looks to run fine no issues that I couldn't fix. It's due for a release by the end of this month. I am planning on making a free version, the first 3 levels (9 stages).. if players like it, they can buy the full version for $1.99 or something like that.
I'm working on an additional 50 hard mode stages and a new upgrade tree, for an update after launch. I am not even an artist, just through lots of practice.
I really like your idea, I think good educational games that are fun and addictive is the way to go, since parents are more willing to spend $ on their kids if they see a potential positive outcome.