Sudoku HD for iPad

- Choose a difficulty and select a puzzle or start the daily challenge. - Tap a cell, then tap a number to place it as your answer. - Toggle pencil marks to jot candidate numbers, or enable auto-notes to keep candidates updated as you solve. - Use hints sparingly to reveal a valid move when you are stuck without spoiling the entire puzzle. - Highlight rows, columns, and boxes to spot conflicts, and turn on error checking if you want instant feedback. - Undo or erase to correct mistakes, track your time and stats, and climb to higher difficulties as your skills grow.