App Name: Sudoku Mega Bundle [iOS Game]
Developer: Diego Acevedo
App Market: Download Page
Sudoku Mega Bundle has 38 unique game modes, some of which have never been seen on the AppStore before! Including Killer, Jigsaw, Skyscrapers, 16×16, Samurai, Word, Duplex, Anti X, Lucky Seven, and many more!
The game has leaderboards, achievements, difficulties settings, easy and smart note taking, saved games, and appearance customization. Finally it is free, universal and no in-app purchases.