the author of this app says:
This is a colorful game that gets your mind smoking. Try to overcome the computer player with triangles of your designated color.
You can play with two, three or four players and choose your opponents' levels. Your objective is to select a triangle that gives you a little bit of the area of the triangles opposite your corner. This protects the area from other players. Did you get all of that?
It's very difficult to explain, but once you start playing, you will get the hang of it quickly.