I use both Mac and Windows, and this add-on is a nice implementation of tab groups on Firefox that feels much like Safari's. The only reason this is short a fifth star is that it doesn't sync with my Firefox accounts on other machines (including my Mac) - so I have to use a workaround. Other than that, I like this.

I LOST ALL OF MY TABS SAVED ON STG GROUPS!!! AFTER SHOW THIS MSG... :((

''
Database error in Simple Tab Groups
Unfortunately, an error occurred while reading data from the STG addon from the Firefox database. At the moment, the addon is stopped. To resume the add-on, do the following:
Restart Firefox Browser (for Linux and Mac OS with process termination)
If you see this window again, try reinstalling the addon:

Remove STG Addon
Restart Firefox Browser
Install STG Addon
Restore the latest STG addon data backup located in the Firefox downloads folder "STG-backups".
You can restore backup in addon settings
''

wish there was a way to view all groups at once
unless there is and i'm just dumb. though it is kind of a hassle to open/change groups since it seems more complicated than chrome's 'just click to show/hide'

works great and has helped a lot, can it be available for chrome or edge? i tried loading the unzipped folder but since its an add on, .yml cant be added to either of the other two.

purely cool

Very helpful since firefox does not have a native tab grouping feature that complements containers. However, tabs are duplicated all the time when you do something such as closing a private tab while non-private tabs are still open. Very annoying.

Very useful! I'm grateful for this extension.

It is really not convenient. I cannot use multiple groups at once, I cannot use pages that are not grouped. Group switching is very slow, 3 clicks are needed compared to Chrome's 1 click show/hide feature. The menu system is VERY un-intuitive.