The king of sudokus, perfect for brain training! Killer Sudoku (aka Sumdoku / Mathdoku) is a Sudoku variant where cells are grouped into cages and the sums of the values in each cage are given. Once you know Killer, you will never go back to Classic again... The app includes lots of cute little 4x4 and 6x6 puzzles, perfect for beginners, with contextual hints to help you learn Killer techniques interactively. From there you graduate to 23 levels of chunky 8x8 and full-size 9x9 puzzles, guarant