Features of Ninja Sudoku: ✓ Logical hint and solver built-in(for both normal sudoku , X sudoku, Jigsaw Sudoku & Killer Sudoku). ✓ No ads while playing the game. ✓ Unlimit logical hint for game and solver ✓ More than 300,000 puzzles and 5000 X sudoku, 40,000 Killer Sudoku, 50,000 Jigsaw puzzles in 5 difficulty levels(from easy to expert), so you have plenty of puzzles to advance your Sudoku skills. ✓ Two selection modes while playing a game(you can change the mode seamlessly when gaming, and