Description: The origin of SUDOKU fever, the Japanese puzzle company NIKOLI Co., Ltd. has released a Sudoku application for iPhone, iPod Touch, and iPad! The name of the application is "Sudoku by Nikoli", it contains 9 free sample problems. You can purchase and add problem collections that contain dozens of Sudoku puzzles at the App Store, via the "Sudoku by Nikoli" application. Please try out the free sample problems. If you like these original Nikoli Sudoku puzzles, we are confident you will also enjoy the new problem collections you add. The problem collections are categorized by difficulty (easy, medium, and hard) on the purchasing pages. When you add a new problem collection, it is simple to choose your favorite difficulty level of Sudoku puzzles. We will keep publishing new problem collections, so you will can continue enjoying our well polished finely tuned Sudoku puzzles as often as you wish. We have worked hard to develop the Sudoku application, and with its original iPhone-like interface it has a great feel, solving Sudoku is smooth and pleasant. [Features] - The application lets you change the orientation of the puzzles to suit you. You can always play Sudoku puzzles just the way you wish. Of course you are able to enter temporary memo numbers when you solve the Sudoku puzzles. - The original Sudoku interface is iPhone-like and it still feels like solving with a pencil. - You can purchase and add new problem collections via the "Sudoku by Nikoli" application. This is a new function for "Sudoku by Nikoli", here you can gather together and enjoy many great Sudoku puzzles using just one application. - There are both save and quit functions, so you can interrupt your play and resume it when you wish. Easy to keep playing with even a little free time. - Your list of problems shows which problems you solved, which you still didn't completely solve, and which are not tried yet. Try to solve all the puzzles! - The application lets you change the orientation of the puzzles to suit you. You can always play Sudoku puzzles just the way you wish. - The application tells you your solution time. A good way to to see how fast you can solve Sudoku problems. - The tutorial tells you the Sudoku rules and how to solve Sudoku. No need to worry if you never did a Sudoku puzzle before.