Great idea, but ... Rated 1 out of 5 stars

... the links to check at the bottom refer to a domain that is apparently long gone.

Gots some goodies but... Rated 3 out of 5 stars

Got some nice tools but there's no way to hide/turn off the toolbar it adds to the bottom of the browser window.
If they change this I'll give it more stars!

Rated 3 out of 5 stars

This is not an emulator mobile devices, but just links at toolkit.

should be Rated 4 out of 5 stars

why be a bar below my firefox screen. should be an icon only.

Rated 5 out of 5 stars

This is an excellent add-on. Bringing these essential testing facilities to the toolbar is going to make mobile development a lot easier for a lot of developers.

There's lots of scope for expansion, but I hope you manage to maintain the simplicity of the add-on. Thanks!

The reference links are also useful, but could possibly do with refining as there's some chaff in there and there are a few biggies missing that I'd like to see - e.g., an intelligent (device-specific) link/utility to DeviceAtlas would be great addition to the Reference section.

Rated 4 out of 5 stars

as a programmer, this add-on helps me GREATLY, to test and check, my lots of errors
thanx

This review is for a previous version of the add-on (1).