Crack! app for iPhone and iPad

In case you’re not familiar with the rules of Crack!, the game is played with 2 to 4 players using a standard 52-card deck. The goal is to win all the cards. You win cards by spotting a matching pair.
At the start of each round, the dealer shuffles the deck and deals out the cards clockwise around the table until there are none left in the deck. The cards are placed face down in front of the players.
The players take turns in clockwise order. If it’s your turn, you turn over the top card from your pile. The idea is to yell "Crack!" as quickly as possible when you see that any of the open cards form a matching pair. Two cards match if they have the same value, for example two kings. The suit does not matter.
The player who yells "Crack!" the quickest wins both piles and adds them to his own stack of face-down cards. This continues until one player has all the cards. If a player yells "Crack!" when there is no match on the table, he’ll have to pay one card to each of the other players.