cher.xpi

after that open your firefox then go to
Tools>User Agent Switcher>Option>Option
then click on User Agent and click Add then fill up this box appears after you click add

* Description: Googlebot
* User Agent: Mozilla/5.0 (compatible; Googlebot/2.1; http://www.google.com/bot.html)
* App Name: Googlebot
* App Version: 5.0 (compatible; Googlebot/2.1; http://www.google.com/bot.html)
* Platform: http://www.google.com/bot.html
* Vendor:
* Vendor Sub:

and your done