I first played this game 50 years ago against a BASIC program that ran on a Teletype™. This app provides a full 3D experience where you can rotate the board around any axis or pinch to zoom. When placing your blue pieces on the board you must click the piece a second time to confirm your move, or click another square to cancel it. There are three levels of difficulty. The highest level plays aggressively using forcing move sequences that result in a win. But the app always warns you if you can block to prevent a win.