This is a machine learning project. The application starts with nothing to know about the game except the rules. Over time, it learns the game by observing your playing style. After each loss, it adds the game to its blacklist, ensuring it never gets checkmated in the same pattern again. However, becoming an invincible player requires more than that. For this, we created game-specific fork lists. If it finds itself in a double-sided checkmate situation, it tries to escape by adding the moves it played two moves prior to the fork list. But to become completely invincible, we added another algorithm that analyzes the games. You can see how much it has learned the game from the graph on the game itself. In accelerated training sessions we conducted on the computer, we found that it learned 99% of 2500 endgames. Now you have an application on your phone that will learn how to play XOX from you :)