This screen cast video example shows you how to install the Firefox add-on as well as extending its functionality by adding several dozen more browser user agent strings by importing an XML file into the UserAgent switcher Add-on. This Firefox plugin is also nice for testing how your website and server environment behave with various other devices or services like crawlers or text based web browsers.
Occasionally I need to view various web projects with mobile devices like iPhone or Droid. Since I don’t have and Android phone I use Firefox and an Add-on called ‘User Agent Switcher’ to do the heavy lifting for me. I have done this type of user agent modification before with Internet Explorer but the process is too tedious to manage. You can read more about it here.
Download the UserAgentSwitcher.xml file which has an extended list of browser user agent strings.