Progress Bar, Bad Select Values, Impossible Cells, Solved Cells, more...
Progress Bar
Auto Sudoku can optionally display a vertical Progress Bar (on the left side
of its window) that tells you how far you are from solving a game. As you
assign given cells, the green portion of the the Progress Bar rises until
the whole bar is filled, signaling that Auto Sudoku has solved the game.
Bad Select Values
Auto Sudoku's Select window can optionally show you values that cannot
be validly assigned to a cell. Bad select values are displayed
on a red background, but Auto Sudoku does not prevent you from selecting
them, and this hint can be turned off.
Impossible Cells
A cell becomes Impossible if it is assigned a bad select value.
Impossible cells are optionally displayed with a red background.
Also note that the Progress Bar fills with red if the board contains
impossible cells.
Solved Cells
As given cells are assigned, Auto Sudoku optionally dislays the
cells that it has already fully solved. Solved cells are
displayed in a different color and can be dimmed or altogether
hidden.