Exit Button Firefox is a simple to use Firefox addon. Go to View menu, Toolbars, Customize... and drag the icon where you want. Exit Button Firefox will also add an icon next to the File menu Exit. item.
After installation, right-click on the toolbar, select Customise... and drag the Exit button to the toolbar, placing it any where you want.

Requirements:
* Firefox

The license of this software is Free, you can free download and free use this browser plug-ins software.