How to use it
Drag the "Shut Down Timer" folder to the right side of your Dock. Now you can right-click (or control-click) on the big red apple shaped timer and select one of the options (5 to 90 minutes timer).
How to STOP a timer
You can stop the timer by selecting the running application and pressing "command-." (that is a dot). As an alternative, just force quit the timer.
This Software is... Simple. There's no countdown shown: this is just a silent, simple, 3-lines-of-code AppleScript that tells the finder to shut down.