Reversi is a board strategy game with 8 rows and 8 columns and a set of black and white pieces for each side. The goal for each player is to make pieces of their color constitute a majority of the pieces on the board at the end of the game, by turning over as many of their opponent's pieces as possible.
You play a piece by touching on an unoccupied square. This puts one of your pieces into that square. The idea is to trap one or more opponents pieces between two of your pieces. Those opponents pieces then change color to become your pieces.
If you cant move, your opponent gets to move again.
When both you and your opponent cannot play another piece, or if every square on the board is filled, the game is over. You count up the number of black pieces and the number of white pieces and the winner is the one with the most pieces. (The ipad counts for you automatically.)