Tic Tac Toe

Tic tac toe (Xs and Os) is a pencil-and-paper game for two players, X and O, who take turns marking the spaces in a 3×3 grid. The player who succeeds in placing three respective marks in a horizontal, vertical, or diagonal row wins the game.

Tic tac toe is great way to pass the time.
Tic tac toe is free.

Modes:
1) Single (Computer)
2) 2 player mode (human)