Features:

* Millions of puzzles
* 30 givens
* A Timer
* Unlimited hints
* Save your game progress
* Free upgrades
* Print your puzzles as black and white worksheets
* Print solution sheets (designed for teachers)

Rules:

1. All blank spaces must be filled with a number from 1 to 9,
2. Each row must contain each of the numbers 1 to 9.
3. Each column must contain each of the numbers 1 to 9.
4. Each Region must contain each of the numbers 1 to 9.