Every player is given equal no. of cards to start with. Each player puts down some cards claiming to be of some number. If other players think he is speaking the truth, they play their turns or if they think he is lying, they can call it a lie and expose your cards.
If you were lying, you get to keep all the cards in the stack, but if you are speaking the truth, the other player who doubted you gets to keep all the cards in the stack.
The most fun card game, can be played with up to 3 more iPad controlled players.