Rated 5 out of 5 stars
Does exactly what I need. This should be standard in Firefox.
Did not find problems in normal use. But I did not test everything that might be possible.
If I could assign shortcut keys so that I can jump directly to a certain group this would be great.
The keys ctrl + ` in Firefox itself is very poor since you just can go from one group to the next or with shift plus the keys above back again.