May not work on non sudoku grids or special constraints. Hotkeys Selection Select cells + Mouse click/drag Add or remove from current selection Move selection +, + Add to current selection + Select all cells + + Deselect all cells + Invert selection, Tool sensitive selection Number Entry Insert value, pencil mark, candidate or colour Insert value, pencil mark, candidate or colour Button Insert value, pencil mark, candidate or colour Change Tool, Next mode +, Previous mode 'Digit' mode ( on German keyboard layout) 'Corner' mode 'Centre' mode 'Colour' mode + Enter digit in 'centre' mode + Enter digit in 'corner' mode + + Enter digit in 'colour' mode Undo / Redo + Undo last action + Redo last action if it was undo Check finished puzzle Button Press the check button to test basic sudoku rules.
