MySudokuGuru app for iPhone and iPad

MySudokuGuru is a program which not only enables you to play Sudoku on your iOS device but will also explain how to solve each Sudoku if you get stuck! The app has the following features:
. A virtually unlimited supply of Sudoku puzzles.
. 6 levels of difficulty.
. Use pencil marks to help solve the more difficult Sudokus.
. Enter your own Sudoku or a Sudoku from a newspaper and play it as a normal game.
. Ask for help - the program will give you a hint or will solve the whole Sudoku.
. Get a step by step explanation of the logic used to solve each box.
. Full undo history so you can backtrack through your game.