Sudoku - Puzzle Mind Game app for iPhone and iPad

Welcome to Free Sudoku puzzle game. Thousands of sudoku puzzles to solve. Lets play and train your brain daily.
Sudoku (originally called Number Place) is a logic-based, combinatorial number-placement puzzle.
HOW TO PLAY
• Mission is to complete the puzzle, you must fill each square on the grid with 1-9 numbers. The numbers 1-9 should appear exactly once in each row, column, and box 3 x 3.

FEATURES:
• 4 different modes to select has a unique solution (Easy, Medium, Hard And Very Hard)
• Intelligent Hint system that you can use when you stuck
• Unlimited undo/redo
• 100% free and offline sudoku game
• Automatic Save and Resume Every time.
Have fun with my Sudoku number game.

Reference sources:
https://freesound.org/people/tim.kahn/sounds/43448/
https://freesound.org/people/Ch0cchi/sounds/15348/
https://freesound.org/people/FxKid2/sounds/367627/
https://freesound.org/people/themusicalnomad/sounds/253886/