Sorry, apparently that extension isn't available any longer. I tried to download that extension from - http://www.inferknow.com/green - and what I got wasn't a "shell", not a complete extension. The Add-ons website went through a major cleanup at the beginning of this year and they pulled extensions made by developers who didn't respond to the emails that were sent about the cleanup. They also pulled extensions that didn't meet the new security and coding criteria that was put in place last winter.