Big Bad Sudoku Book is FREE today! https://itunes.apple.com/us/app/big-bad-sudoku-book/id364907966?mt=8 If you already got the free version I recommend clicking over to get the full paid version today. -Michael Smith Bad Weasel Games
I downloaded this, and while I haven't played Sudoku in a long time, I really do like this app. Since it's free (for now) I would recommend giving this a try if you do like Sudoku.