Using a desktop browser plug-in or user-agent switcher is not ideal for testing mobile web apps or web sites in general on mobile. It's just a bad idea.

If you need testing software that will run from your PC and simulate a variety of mobile devices, I'd recommend a 3rd party software built specifically for this purpose, not a browser's user-agent switcher.

One that I have some experience with, professionally and personally, is DeviceAnywhere. IMO, it's about as close as you can get without actually having each type of mobile device in your hand, though at times its response time can be on the slow side. Read about it here to see if it might fulfill your needs - I'm sure there are others out there as well but I don't have experience with them: http://www.keynotedeviceanywhere.com/

Using a desktop browser plug-in or user-agent switcher is not ideal for testing mobile web apps or web sites in general on mobile. It's just a bad idea.

If you need testing software that will run on your PC and simulate a variety of mobile devices, I'd recommend a 3rd party software built specifically for this purpose, not a browser's user-agent switcher.

One that I have some experience with, professionally and personally, is DeviceAnywhere. IMO, it's about as close as you can get without actually having each type of mobile device in your hand, though at times its response time can be on the slow side. Read about it here to see if it might fulfill your needs - I'm sure there are others out there as well but I don't have experience with them.