Question creation function You can capture the number place problem of 9x9 squares. To capture the problem, use the camera attached to the smartphone to shoot. Please shoot with as little distortion as possible and without creating shadows. Redo function You can step back in steps. Level judgment function The difficulty level of the problem is judged independently by 5 levels. Memo function You can make a small note of the possible numbers for each square. animation We will inform you by sou