Sudoku Classic Fun:6400 Levels

6000+ unique number puzzles to give your mind a real workout!
Features:
1. 4 difficulties from easy to master.
2. Auto save progress of each level and you can continue whenever you are free.
3. Highlight duplicates and conflicts to avoid repeating numbers in a row, column and block.
4. Make notes to keep track of possible numbers in the free cell.
5. Hints, auto-check, and duplicates highlight.
6. Use tips to help solve the puzzle easier.
7. Undo your input.
8. Colorful highlights of different cells.
Enjoy the brain teaser on your phones and tablets!