555!

Tap the buttons to place numbers on them so that they sum up to 5. The numbers can sum up to 5 along the row, column or diagonally. Numbers get cleared up when they add to 5 so that more numbers can be placed. When none of the rows/columns/diagonals add to 5 and the 9x9 cells fill up, the game is over. The game supports two modes - infinite and timed mode. Friends can challenge each other for high scores in timed mode.