Rules of the game Gem Blokus:

- A board with 20 * 20 squares.
- 4 players having each 21 pieces : 1 single-square, 1 domino, 2 triominos, 5 tetraminos and 12 pentaminos.
- As player, I shall place on the board most of my pieces.
- For first round, I must place a piece so that it touches one of the corners of the board.
- Next, a piece must be placed so that it touches a corner of one of my own pieces. It may touch several corners, but never any edge of my pieces!
- If I cannot place any more piece I pass my turn.
- The end of the game is reached when every player passes.
- My score is : addition of all the squares of the pieces I placed.

The app does collect user data, all the data is saved only on the mobile device.