This app allows users to play the exciting "Sandwich" variant of Sudoku for free with no ads. Also known as "1 through 9 Sudoku", this variant gives additional clues telling the user the sums of the numbers between the 1 and 9 in each row and column of the puzzle. For instance, if a row contains 2 and 6 between the 1 and 9, the additional clue would show the number 8. This app is free and may include additional requested features in the future.