LadyBirdSudoku

LadyBirdSudoku (originally called Number Place) is a logic-based, combinatorial number-placement puzzle. The objective is to fill a 9x9 grid with digits so that each column, each row, and each of the nine 3x3 sub-grids that compose the grid contains all of the digits from 1 to 9.
FEATURES:
- different difficulties
- hundreds of puzzles for each difficulty
- hint system
- auto-save your progress for each puzzle
- unlimited undo/redo
- selected cell highlight
- number highlight (optional)
- clean interface and smooth controls
- phones and tablets support