Challenge your friends with the classic game: Rock Paper Scissor.
Rock Paper Scissor is very easy and in this version is possible to play with your friend on the same device.
This app is for two gamers.

Every player has is keyboard with three buttons (Rock Paper Scissors)

Instructions:
- Stay at the buttom of your device and your friend at the top.
- Press "START" button
- Wait countdown
- Click on "Rock Paper Scissors" buttons

The game has only three possible outcomes other than a tie: a player who decides to play rock will beat another player who has chosen scissors ("rock crushes scissors") but will lose to one who has played paper ("paper covers rock"); a play of paper will lose to a play of scissors ("scissors cut paper"). If both players throw the same shape, the game is tied and is usually immediately replayed to break the tie. Other names for the game in the English-speaking world include roshambo, ick-ack-ock, ching-chang-walla (in some parts of South East England), and other orderings of the three items, sometimes with "rock" being called "stone".

(from http://en.wikipedia.org/wiki/Rock-paper-scissors)

Enjoy!