Sudoku

              Sudoku, also known Number Place, is the most popular logic based number-placement puzzle in the world. Fill the 9×9 grid with digits so that each column, each row, and each of the nine 3×3 sub-grids contains all of the digits from 1 to 9 now!

How to play:
 - Each Sudoku has only one true solution.
 - Place 1 to 9 into each grid cell
 - Every cell is part of a cage, indicated by dotted lines.
 - The sum of all numbers in each cage must match the value in the upper left corner
 - Each cage, row, column or 3x3 region does not have numbers repeated

A fun Sudoku game with thousands of puzzles. Can show conflicts, give hints, and fill in pencil marks if you want it to. Supports "undo" in case you make mistakes. Simple, but complete game with four difficulty levels.