Aren’t there already enough sudoku games on the iPhone?

Probably.

How does Colouroku generate new games?

The top left 9 squares and bottom right 9 squares are randomly filled (all other squares are left blank). Colouroku tries to solve the rest of the squares. Sometimes a solution can't be found, in which case we start over. Finally, with a full board, some squares are removed (7 * the difficulty level + 2).

How does Colouroku solve a game?

Colouroku solves a game much in the way you would — by comparing other numbers in the row, column, and square to eliminate possibilities and occasionally guessing. This process is repeated until the board is solved or Colouroku gives up.