So far the best replacement for the old tabgroup plugin by far. I recently just downloaded this and trying out, but I'm really impressed. Love the memory saving settings when you got tons of tabs in different groups. Will come back if I find some bugs, problems or suggestions!

EDIT: So a couple of things I noticed:
When trying to open a group as a new window does not work, sometimes it just opens a new blank page. It would also be nice if there was an option to take an already open window with tabs and create a group from that, rather than just one tab at the time. I don't know if it's documentet somewhere if there is a way.
When clicking or hover over the Tool tips (?) does not seem to do anything.

Correct me if I'm wrong!

This looks great, just started using it and it seems like a good replacement for the old Tap Groups

This is a very useful extension. I wouldn't say it's simple, but it is powerful.

It's useful to be able to move tabs into groups based on their URLs; I use this to separate different projects so that I can switch context between them.

It doesn't seem to play well with other extensions that automatically close tabs in the background, though; for example Dustman. After a tab is auto-closed, when I switch to that group, STG says “Invalid tab” and “Background not inited”. After that, STG doesn't work. If I disable and re-enable it, the toolbar button never finishes loading. Restarting Firefox seems to fix it. (I think this may be the same issue as #212 on GitHub.)

Edit 2018-07-20: Thanks, I've updated to 3.0.10. Let's see how it goes!

Edit 2018-07-23: I'm still seeing “Invalid tab” notifications that stop STG from loading the group, but I haven't yet seen a “Background not inited” one, and STG starts working properly again when I reload it from the menu.

Needs some work, but I am grateful that someone came up with a replacement for the old tab groups. It would be very helpful if there was a button to open the grid view directly from the browser GUI, not via the Simple Tab Groups button, i.e. with one click instead of two.

Given the poor state FF API has been in ever since Quantum, this is as good a replacement for Tab Groups as can be expected. There is a rather unfortunate and extremely annoying issue where when you switch to a different group, your current tab moves to the new group, but otherwise it seems to work more or less as well as you could expect. I wish there was an option to close the "group management" tab when you select a tab in it, the way group management worked in tab groups.

In this version of Firefox 61.0 the tabs are hidden in all the sites except the thumbnails of the Windows taskbar where all the groups of all the groups are shown together. I think it did not happen before. Just fix this so that the extension is perfect and 5*

Edit 1:

Thanks for your response. We hope that later it can be fixed (the thumbnails are very practical).

Another error that I have found is that when closing the last tab of a group, instead of appearing the Newtab page or disappearing this group, the last tab of the previous group is moved there. I've only been able to try it with 2 groups.

All good but would like the ability to leave tabs loaded when switching groups. Would save a lot of logging in and out. As someone else said, if the memory gets out of hand, closing and re-opening is easy. Yes, that also means losing logins, but it's the difference b/t logging in and out of sites several times a day (current) and re-logging-in to sites after a week or more when it's time to restart. A lot of people wouldn't need it, but the option would be great.

Really great to see this extension, but please please allow the user to select whether or not tabs are closed in the current group when switching to a new group. I would even suggest to make it the default to keep all tabs open when switching since the current system of closing tabs will cause more headache, confusion, and mistakes from your users than any benefit like a lower memory footprint would make up for. It takes 5 seconds to close and re-open FF if you're looking to free up resources.

Great working app. Works fine and provides the missing functionality after the recent switch of app functionality. Great that it also describes the reasons for the required permissions. Still would like to see that 'Access your data for all websites' requirement is removed, this permission just for favicons seems a bit overkill.

Would be better to use tabs.hide() from firefox 59.

Awesome!

Would be great if you could add the option to show the group NAME I am in at the moment.

PS
Please also consider to use the Awesomebar special charakters (%,~,#,..) in your search field!
PPS
Invalid tab ID: 788 appears more and more often! Please fix it! We are losing tabs!

Like bellow, quick change groups is difficult. add-on have a slow response.

Add seems to have a bug, if last tab is a new empty tab is selected, impossible to switch btw groups.

i need to clic another tab to have the possibility to switch.

Other things. Is it possible to add option to don't reload the active tab?
When filters on a site are activated, all is reset like a new visit.

1 star and it's perfect

Tab Group reborn (almost)

Almost there. I loved the free arrange of groups on the prior version; but I understand it is coming in the future. Best Tab grouping out there, bar none. Easy to see icons, great graphical interface, easy to export. In fact, the reason I delayed updating to the latest Firefox was because Tab Groups was not in place. Now it is.

It doesn't switch between the tabs but instead closes and reopens the tabs. Every tab on the group is reloaded. You can use https://addons.mozilla.org/firefox/addon/experimental-simple-tab-groups/ from the same developer for proper tab hide/show but its experimental.

Добрый день! Все хорошо, только есть один момент. Если в группе много открытых страниц-то хочется их закрепить. А если закрепляешь-то при открытии новой группы закрепленные страницы открываются и в новой группе. Если бы это можно было бы исправит-было бы здорово

It's fast and almost never crashes at least in my case, which makes it even less time-consuming than the old add-on. One thing I don't like about it is that it messes the order of the tabs when switching from one group to another. Hope the developers will fix this issue in upcoming updates. Then I guess it'll deserve a 5-star rating.

Great addon, makes me forget old native tab groups. Improving a lot

It is a first that is nearest Tab Groups.
Make it better tabs overview (managing groups) and you have 5 stars and recommendations from me!
https://addons.mozilla.org/cs/firefox/addon/tab-groups-panorama

Good Addon. Not sure if the means of always closing tabs when switching groups is a generall problem with firefox 54+. Ofc it would be nice if they could stay opened. Let's see how it goes in time.
One other bug is, when I close the browser and reopen it: the tabs from my session reopen without a problem (they are not lost) BUT they are in no group anymore. Would be nice if the addon recognizes this was the old group and uses it. Workaround (and general nice feature) would be: when you right click tabs you can move them to group, so having a second option, when clicking on a tab to "Move all open tabs to group ..." would help a lot :) so I at least dont have to click on every single Tab of a window. Good work so far!

Poor compared to Tab Groups but better than anything available yet in Quantum disaster and makes it barely usable.

Almost as good as the old Panorama feature.

Some rough edges, but it's getting there.