You know the game and there are plenty of versions of it about. This one comes with a lot of nice extras. There are the usual four levels of difficulty as well as a puzzle solver and the option to add answers in pencil before making the bold move of writing in indelible ink.
What is a little different from most of your Sudoku fare is that the Resco version allows you to create your own Sudoku puzzle. Now I might be stupid but I'm not totally sure this is possible. If I create my own puzzle then by definition I'm actually solving my created puzzle at the same time. Which either means I'm going to save a lot of time or I'm just putting numbers into blank boxes like I would with any Sudoku. Perhaps the game really means 'randomly generate' new puzzles. Also you can copy a Sudoku puzzle from a newspaper and put it into your mobile phone for safekeeping.
Create your own Sudoku puzzles or copy them from a newspaper