the author of this app says:
Remember those schoolyard days, when you and your best friend played that notebook game, in which you had to make a box by joining four lines, thus earning points?
But if you do, Mosaic will bring 'em back for you.
It's a bit more interesting this time, though, especially since you're playing against your computer.
Mark my words: With Mosaic around, it's not easy to make a box for yourself!