Matrix Sudoku

Matrix Sudoku is a popular and Brain-Training puzzle , that consisting of a grid of 9 by 9 numbers. Each grid number is in the range 1-9 which can only occur once in any row/column combination and the 3x3 square in which it resides. ('Sudoku' is a Japanese word that meaning "the numbers must be single", or "the numbers must occur only once". )
The goal of Sudoku is to fill all the blank squares in the grid with the correct numbers.
In Matrix Sudoku, you can save /load games and print the puzzle. Matrix Sudoku also support the variant sudoku: Nonomino Sudoku, also known as geometric Sudoku. This variation most closely approximates regular Sudoku, but instead of nine 3x3 groups, it has nine groups in irregular nonomino shapes.
Features:
Millions of different possible puzzles. Three difficulty levels from easy to hard.
Check correctness as you go along.
Hints available when you get stuck.
Print out the puzzle so you can play your sudoku on pager.
Automark the empty places, in this way showing you the possible solutions for a square.
Variants:Nonomino Sudoku, also known as geometric Sudoku also included.