This app is a master class reversi application that you can play with 7 computer players. If you want to know how much real computer player is strong, play with "Computer".
"Computer" is strong than almost all reversi AI include PC version. So normally you can't win.
But another computer players have weak points and go easy for you. So, you might win.
In this application "Sigh and Cheer" sound effect and "Comments of computer" are made from the game situation. So, you might play each move as a puzzle.
And when you seem to have got bad move from sound effects or comments, you can "Undo".
Furthermore, you can see evaluation value of reversi engine. If you want to defeat computer players, use these functions.