Welcome!
First touch one of the game modes to start the game.

You will be asked about the game options. The amount of options depends on the selected game mode. On "Addition before" mode the specified additional time is added at the beginning of a turn.

Touch the screen to start the game. When the game is running, players touch the screen to end their turns. Some information about the game is shown. The game can be paused from the pause button and also gets paused when the application goes to background. The screen is kept on during a game unless its paused or  an individual turn has lasted over 30 minutes.

But don't waste your time. Red mark means that white has lost the game.