Recommend SudokuDragon 18

Solves and generates Sudoku puzzles
Download new daily puzzles from our web site.
Type in and solve puzzles printed in Newspapers.
Unique Sudoku stripe included in puzzles
Choose from range of display themes for great range of color and patterns
Gives hints and suggestions on how to solve a puzzle.
Support beginners and expert players alike.
Unlimited undo and redo of square allocations for when you need to backtrack.
Print out a sudoku puzzle for solving by hand.
Support for 4x4; 9x9 and 16x16 sized