Black vs White for iMessage

Challenge a friend to a game of Black vs White (Reversi)! Now on iOS 10 for iMessage!

This is a 8x8 strategy board game.
A move is made by placing a disc of your color that "sandwiches" discs of the opposite color.
A line of discs is sandwiched/out-flanked when it is surrounded at the ends by discs of the opposite color. Surrounding must be horizontally, vertically, or diagonally in a straight line. Sandwiched discs of opposite color will be flipped to your color.
Players take turns placing discs until no more moves are possible.
The player with most discs of his color wins!