That's one of doing it...the other would be something like this [1]. Not ashamed to say I had to beat the whole thing the first time I saw it because it was so brilliant. And I normally hate pointless puzzle games.
More apps should have a video showing you the gist of what's going on like they do.
that's look really really interesting! I was actually thinking of looking into tablet apps that teach kids stuff like that in a fun way. Thanks for the link, I'll check it out