Very user friendly interface. Before i use other addon, but without option to select version of browser and etc, just only select os and browser.

just works :)

Wow it is easy to use and portable too. thank you!!

so good and portable.
there are many UA lists to select

So muvh

They popped up an ad begging for a review when I was doing something, and then when I removed it I get a "why did you uninstall". I'd expect that in Chrome not FF.