the author of this app says:
This is a fun yet challenging game with one objective -- to get three balls of the same color into a line, vertically, horizontally or even diagonally, to make them dissapear. Sure, it sounds easy enough. But for every move you make, another three balls appear, sometimes blocking your path. Okay, so that isn't challenging enough for you? Make it harder by increasing the number of balls you have to line up.