Sudoku4ever Free

Very interesting app for passing time. Nice feature to give hints. Though a bit disappointed in that the hint was actually wrong. Wrong hints based on flawed pencil marks (All pencil marks were not filled by me in when asking for a hint. Application apparently is supposed to fill in all the rest of the pencil marks, but did not manage to do that correctly. Instead the application gave hint based on those flawed pencil marks.) instead of the actual board setup.