More additions: Drawing Mode Toggle and Grid Pattern

Toggle between the Drawing Modes:
You can toggle between the drawing modes by using the space bar. The default is always FREE. Hit the space bar to switch the mode to LINE. Hit the space bar again to switch to AREA mode. One more hit on the space bar and you are back to FREE.

Add Pattern to the blank grid:
Ctrl-Q adds "?" to the blank grid.
Crtl-Q clicked again will remove the pattern.
Show/Hide the Pattern is available through the menu as well:
View --> Check/uncheck Show Pattern
Your selection will be saved as default.

Keep the scale of the puzzle window
If you resize the puzzle window the system remembers your zoom settings. All the puzzles window will have the same scale.
Use Reset All (the last item on the left menu) to go back to the system's default settings.