Sudoku - Classic Sudoku Games is a free iPhone game developed by yong yin that offers an endless supply of Sudoku puzzles. The game is designed to be intuitive, polished, and enjoyable for players of all skill levels.

Players can choose from four levels of difficulty: Simple, Medium, Hard, and Master. The game also includes helpful features such as hints, auto-check, and duplicates highlight, which can be used to make gameplay easier. Players can also choose to complete the challenge without any help.

Overall, Sudoku - Classic Sudoku Games is a great way to train your brain while having fun, and it's available to play anywhere, anytime.