Sorry, the bugs I said were my fault. An adaware had changed my Firefox settings. Now it is fixed and the add-on works correctly. Simple Tab Groups works fine again.

Great mod! 5 stars for the value it adds despite having a hard time getting regex to work.
Wanted to move over many of my tabs using regex but couldnt get it to work at first. Thought it must be broken, but after moving manager and a couple of tabs to a new window and then back again it suddenly worked like expected (catch when refresh/active tab). A couple of tabs it still still refused to catch on reload so copied the address to a new tab and then it caught it for some reason. (Only had such problems with tabs that existed on installation. New ones are always ok it seems)

This add-on has worked superbly for ages, and has grealy improved my browser experience.

A minor bug in the recent update has prompted me to review an otherwise flawless add-on, not because I'm irked, but because the devs have responded to the bug enquiries swiftly, concisely and clearly. Ironically my faith in this add-on has been raised even further.

I definitely recommend this add-on!

Updated to 5 Stars since the issue I have seen has been fixed in the update. Great Addon I have installed in all Firefox installations I am using.

FIXED: Unfortunately, the latest version (4.4.2.1, from 26 Feb 2020) contains 2 major bugs, which ruined the previously awesome add-on:

1) When I now click the STG icon in the Firefox (v73.0.1) toolbar, the add-on shows me a listing of the _tabs_ in the active group, rather than a listing of all the _groups_ that I have created.

2) The "Move tab to group" functionality (from right-click context menu) no longer works. It seems to do absolutely nothing now.

(Assuming that the above bugs will be fixed soon, I'll gladly recommend the add-on to all users!)

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EDIT (5 March 2020): Yes, the update to v4.4.2.5 indeed fixed the bugs mentioned above. Superb! Thank you Drive4ik. =) =) =)

Дополню сообщение gamover
Версия 4.4.2.4, последнее обновление 26.02.2019, новые обновления не находятся. Кнопка TabGroup все еще показывает по умолчанию не список групп, а список вкладок в группе. Раньше было наоборот

Last update changed it to show all the tabs in your current group rather than the groups, making it extremely tedious to switch between groups. The addon is much less useful now. Edit: Fixed

If you use a lot of tabs and like to keep your sessions organized around themes, this is an essential tool. Don't leave home without it!

upd: Now that I understood, how to use regular expressions with this extension, it's become really helpful. Thanks for your help.

Hi. Love this! Took me a while to replace tab groups but finally I found this! Great job. I'm loving the workflow improvements it brings and it's first class in reliability too. Thanks you for creating this for everyone crying about the loss of tab groups, this is actually better!

DEV: One thing i'm not certain about is if it's possible to include pinned tabs under tab groups i create, is this possible?

This addon saves my ass. An incredible addon.

Has minor issues, but it's great. Went essential in seconds. Thanks, keep up the good work!