Ultimate Tic-Tac-Toe takes the classic game of Tic-Tac-Toe and adds a strategic layer to it.
Instead of a normal game of Tic-Tac-Toe each square contains another smaller game of Tic-Tac-Toe, and just to make things a little more difficult you are not able to freely place your X and O's.
Where your opponent played their turn dictates where you can play on your turn. Here is an example: if you place an X in any top-left corner your opponent now has to play on the top-left board. If they then place an O in the bottom-right corner you no have to play on the bottom-right board.
The game has a singleplayer with 6 difficulties, local multiplayer, and will soon get online multiplayer.
The game contains NO ADS and the only in-app purchase is an option to buy the developer a cup of coffee.