Killer Sudoku is a Sudoku game for those who love counting. In addition to the usual rules (numbers 1–9, no repeats in rows, columns, or 3x3 squares), the board is divided into dotted blocks with a number in the corner: the sum of the numbers within a block must equal this mark, and no numbers within a block are repeated.
There are fewer open numbers here than in the classic version, which is the key to solving the sum. A great warm-up for mental arithmetic and logic at the same time.
What's inside:
• Convenient input: select a cell and press a number; "Erase" clears the error.
• 60 levels of three difficulty levels: Easy, Medium, and Hard—20 in each.
• If stuck, "Hint" reveals the correct number; "Clear" restarts the level.
• "Rules" screen—how to play, right from the main screen.
• Works offline; progress is saved.
Sum, exclude, and include—and the grid will converge.
The app is free and contains ads.
Killer Sudoku: classic 9x9 plus dotted squares with sums. 60 levels.