With 4 difficulty levels, intuitive intece, and all the functions right at your fingertips, this Sudoku app is sure to be your favorite. Interrupted? Exit Sudoku, and the puzzle is saved exactly as you see it!* 4 levels - easy, medium, hard, extreme* Pencil marks with auto fill / erase.* Auto-save* Undo* Intelt hints* Selected digit highlighting* Incorrect entry highlighting* Social network sharing* Leader Board is coming soon