Green Sudoku easy to operate!

300 Sudoku you can play for free! A popular Sudoku in the world as a pencil puzzle, it will play free of charge 400 questions! Let's train the brain! Easy to operate! It is easier to operate than other Sudoku apps! 9 Mass buttons are easy to push. When you press a long press to enter numbers immediately, It has undo, redo function, copy and paste functions. There is automatic saving, so you can play it in your favorite time. Assist function is also fulfilling! Tell me the duplicate numbers, It tells us the duplicate numbers, the same number as the currently selected number and the memo glow.