• Puzzle generator for unlimited play
 • Eleven difficulty levels
 • Tutorial teaches you new techniques
 • Large, high contrast digits are easier to read
 • Automatic or manual pencil marks
 • Highlighting helps you discover patterns
 • User interface optimized for fewer touches
 • Choice of five color schemes
 • Never covers up the board while you are playing
 • Infinite undo/redo
 • Choice of digit styles, including Kanji and Hanzi