If you need helping solving Sudoku puzzles, Swamp Numbers is the program for you. After entering a puzzle from a book or newspaper, you can do the puzzle with Swamp Numbers identifying errors you make and providing hints when you are stuck. For difficult puzzles, Swamp Numbers allows you to enter candidate values in each cell to help you apply more advanced solution techniques.When you don’t have a puzzle book, you can have Swamp Numbers generate a puzzle. Nine levels are available ranging from simple puzzles to those that will challenge experienced solvers.

Sidenote: At the point of posting this program has been marked as beeing freely available without costs. As this program is hosted with the AppStore the status might change. Authors like to publish their programs for free for promotion purpose and then make it commercial. Also it could happen that the author decides to take the program down.

http://appshopper.com/games/swamp-numbers