SumIt is a game played in two on a 9x9 board. In each box there will be a random number between -9 and 9 (0 included), alternating positives with negatives.
The first player (highlighted in white) starts by selecting a number from the first line - tap once to select, tap again to confirm. You can see the selected number in the middle box. The numbers each player select add to their current score. Making a selection is required.
The second player continues by selecting a number from the column activated by the number the first player selected - tap once to select, tap again to confirm.
The game ends when a player selects the last number from a line or from a column.
The player with the higher score wins.