Classic Sudoku-leisure puzzle

Sudoku is #1 classic Sudoku game you know and love for your phone and tablet, and the best way to learn and improve your skills in this classic puzzle game.
Sudoku has 4 difficulty levels, intuitive interface, 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!
Features:
* 4 levels - easy, medium, hard, extreme
* 3 input methods - digit first, cell first, popup
* Pencil marks with auto fill / erase, as specified in settings
* Auto save
* Intelligent hints
* History scores
* Selected digit highlighting, as specified in settings
* Incorrect entry highlighting, as specified in settings