You will find a lot of Sudokus in newspapers, magazines and books. Sometimes you need help to solve the Sudoku or have not got something to write with you. In such cases, the app is handy for your smartphone ot tablet. If you wish, the app can show used numbers and hide or show possible candidates for a cell. When you want, you can also ask for a tip including the reason why. Of course you can also save a Sudoku and retrieve it for later solving. The numbers appear in different colours: blu