sudoku ultra app for iPhone and iPad

■ Introduction
Sudoku is a logic-based, combinatorial number-placement puzzle. The objective is to fill a 9×9 grid with digits so that each column, each row, and each of the nine 3×3 sub-grids that compose the grid contains all of the digits from 1 to 9 (wikimedia).

Sudokus game rule sounds pretty simple but it has a long history and very challenge to any brain whose likes mathematic game.

You might think that Sudoku is Japanese game due to its name that sounds like a Japanese word but this game was first introduced in France in the late 19th century. However, it has become popular since 1997 when New Zealander and retired Hong Kong judge Wayne Gould developed a computer program to produce puzzles quickly. He named it Sudoku and brought it out to the world.

Sudoku is very popular game now. Even there are so many contests and TV game show about it. You also find a lot of PC/mobile Sudoku but what we are please to introduce to you here is a different experience. SUDOKU ULTRA! Try it out and enjoy!

■ SUDOKU ULTRA features:
- Never-ending game: puzzles are produced unlimitedly and totally FREE.
- Three difficulty levels: Championship > Premiership > World class.
- Help on Facebook: Share current state to ask friend on Facebook for help.
- Very useful number pad: Highlight indicated number / draft number. -> help you consider solutions better.
- Top 50 players over the world: compete with other players and join leader board of top 50 best players over the world.