To navigate around the Sudoku game board, you can tap each cell with your finger. A keypad will appear which will allow you to enter a number by touching a desired digit.
The 'validate' button can be tapped to check for valid and invalid cells. Valid cells will glow green whilst invalid cells will glow red.
The 'hint' button can be tapped which will automatically populate a cell with a correct digit.
To navigate around the menu, you can tap the desired menu item with your finger and use the on-screen arrow to go back to the previous page.