BrainSquare: free puzzle app game for iphone, ipad

BrainSquare is a free puzzle app game. The object is to line up red squares to connect the red dots.  Then do the same for white dots and yellow dots.

There are 20 free levels and I've solved them all. But I don't truly understand the mechanics/rules.

The graphics are definitely slick. I think I'm going to redo them to get a better feel.