When starting the app the camera preview is shown with green borders indicating that it is ready to scan a sudoku puzzle. It is worth mentioning that in order to get a solution the user should play around with the distance a bit (some sudokus might be recognized better when the camera is close and others work better with a medium distance) and he should also be patient which means trying certain distance for several seconds and not permanently moving the camera. When a sudoku puzzle is detected and it has a valid solution the user is immediately taken to another screen showing the solution. Be aware that not every sudoku can be detected.