Most useful addon/extention in the store!
IT IS A MUST HAVE & SHOULD BE NATIVELY INTEGRATED IN ALL BROWSERS!!!

However i have some recommendations:
1. More settings for customizing the manage groups view.

edit: And we need Subgroups :D

1.1 Fold/Unfold a specific group or a pair of groups (fold custom topic 1 only) the folded group now only shows custom number of entries [i have too many groups they dont fit onto my screen at once, even with my 1,20 meter wide monitor+second monitor setup lol]

1.2 Highlight tabs that are currently loaded (text color+backround should be both customizable to avoid people in dark mode or with dimmed screens seeing the difference)

Fantastic interface and I love the backup feature.

This extension is a must. Its features should be built-in into Firefox.

You can use it in a sidebar thanks to the "Show sidebars" button that you can add from Firefox customization. That gives you not only tab groups but also vertical tabs that have become something essential to me no matter the browser I use.

I normally create and delete groups dynamically without skimping. Every time I start doing something I create a group just for that (even if at the end it only required one tab) and delete the group afterwards.

Very intuitive UI, supports color codes and regular expressions! Feels awesome!

Unfortunately Firefox doesn't have a very good Profile Manager, the onboard one is very primitive (unlike other browsers).
I tried this instead, and it works well. I have different subject areas arranged in different Tab Groups. It is easy to stay organised, and switch between subject areas.
Works really well for keeping your Tabs organised.
Has a built-in backup tool which I regulalrly use!
Update: I now use shortcuts to open the 'Groups Manager' for ease of managing, also for a manual backup, before I make any changes.
Great tool for organising different subject areas while you're working.

Loving it.

Question: I am getting a folder in my bookmarks called Simple Tab Groups backed up to my bar periodically. It contains every open tab as a bookmark neatly organized. I don't know how I did this.. I can't locate the option again. Is it part of the add-on?

I love this add on, it's great! Could you all make it compatible with android Firefox?

Shortcut are not working but is great