Sudoku (aka Number Place) is a game where you fill a grid so that every column, row and 3x3 box contains the digits 1 to 9.
To solve the puzzles a simple depth first search is used (balanced to search cells with lowest number of candidates first) combined with single candidate matching and rejection of unsolvable sudokus. It will solve most sudokus in a few seconds.
Other features include Open and Save, Copy and Paste, lock a sudoku (stops you from editing the values of a starting sudoku), three different themes, a background of Buttons the cat, 36 premade sudokus (from easy to evil) and source code.
Sudoku Solver was made in RealBasic and is available for Mac and Windows. For more of my witterings see my developer journal.