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