Chess Challenge app for iPhone and iPad

Chess is a two player strategy board game played on a checkered board with 64 squares arranged in an eight-by-eight grid called chessboard.
Each player begins the game with 16 pieces : one king , one queen, two rooks, two Knights two biships and eight pawns. Each of the six piece types move differently. The objective is to checkmate your opponents king by placing it under an inescapable threat of capture. To this end, a players pieces are used to attack and capture the opponents pieces, while supporting their own. In addition to checkmate, the game can be won by voluntary resignation by the opponent, which typically occurs when too many pieces are lost , or if checkmate appears unavoidable. A game may also result in a draw in several ways, where neither player wins.