I'm trying to create an application that allows a player of any level to enjoy the game.The goal of the game is to checkmate the other king.

Chess Rules

King can move exactly one square horizontally, vertically, or diagonally. At most once in every game, each king is allowed to make a special move, known as castling.
Queen can move any number of vacant squares diagonally, horizontally, or vertically.
Rook can move any number of vacant squares vertically or horizontally. It also is moved while castling.
Bishop can move any number of vacant squares in any diagonal direction.
Knight can move one square along any rank or file and then at an angle. The knight´s movement can also be viewed as an “L” or “7″ laid out at any horizontal or vertical angle.
Pawns can move forward one square, if that square is unoccupied