This addon stays simple and do whats expected. I removed the tab bar thanks to a Stackoverflow topic. Unfortunately the keyboard shortcuts allowed by Firefox are limited to... Ctrl+Y ! I left the side panel button on the interface to help the usability.

It's pretty cool, but it lacks some features that I need.
1) for example I have like 300 cards open at the moment, it would be nice to have a button somewhere to automatically group them by domain (because I have to click on every different domain and group it separately, right now. It takes a lot of time.

2) an option to group new tabs after opening them? After I open new youtube tab (while being outside of any group), it should be automatically grouped into the "youtube" domain group. So I don't have to do that manually.

3) a button to collapse ALL groups at once?

4) another thing that is bugged - after I close the Tabs sidebar (the whole plugin sidebar) and open it again, only a few groups are kept (seems to be random ones), or only a few cards are kept within a group. Most of them need to be created again, which is troublesome. Both for normal and domain groups. Most of them disappear after closing the sidebar. Only a few are kept.

thank you for your work

Exactly what I needed! Can you maybe do it so it auto groups by domain? Example wikipedia.org 20 pages open and it automatically groups them?