When you play against another human, the initial board setup looks like this:
The player who chooses the light pieces moves first.
Before and during every move, the current player will be indicated at the bottom of the board.
You can click Quit at any time to exit the app.
The first player can now drag and drop one of the light pieces to a legal point. (Instead of dragging and dropping, the player can also click on the piece they want to move and then click on the destination.) This may be a regular move or, if a jump is available, a jump over one of the opponent's pieces.
If the player has jumped over one of the opponent's pieces and an additional jump is available, the player will be notified that they have to Keep jumping.
By default, a player doesn't have to play a piece even if they've already touched it: The player can simply click on a new piece and make a move with that piece instead. In the preferences, you can activate the touch-move rule, which forces players to move a valid piece once they've touched it, like in chess.
Once the first player has released their piece, the opponent with the other color can make a move in the same way.
Once one of the players wins a game – or the game ends in a draw – the win or draw will be tallied, and you'll have the option of playing another game with 0, 1, or 2 players.
A player can click Resign at any time when it's their move. A win is chalked up for the other player, the board is cleared, and you're returned to the main menu.
By default, takebacks are allowed. At any time, clicking on the back arrow takes back the most recent move, allowing that player to make a different move instead. Play will then resume with the other player.
Takebacks can be disallowed in the preferences. This will remove the back and forward arrows from the game board.
If takebacks are allowed, the players can click the back arrow as many times as they like, all the way to the beginning of the game. They can then use the forward arrow to step forward through the game they've already played. At any time, they can override any of their moves and continue play from the new board configuration.