Was pretty excited about getting a replacement for Tab Groups for Firefox. However, I just installed this on a new install of FF and it appears to be a bit flaky. There are tabs that appear and disappear by themselves. Will update my review if I can figure out what's going on, but for now, it's not ready for primetime.

EDIT: FYI I tried to import tabs from my other computer that has Tab Groups installed. When I tried to import tabgroups-prefs-20180809-153817.json I got a message saying "INVALID FILE".