Challenging sudoku for the iPhone!
At first I didn't think it would be feasible because of the smaller and limited interface, and I will grant that it was difficult to adjust to the sizing, but this game is just as challenging and rewarding as the computer app.
For anybody who has played 3Doku before, it will take time to adjust. For new users I imagine it might be confusing initially but the in-app guide is clear and very helpful.
It's refreshing to find a sudoku game that is consistently challenging and entertaining, and 3Doku has really lived up to and exceeded my expectations.