Was looking for this for ages.
There's always space for improvement (bookmarking a tree w a single bookmark, hiding top tabs...), hope they/you keep up improving it. But it is best I've seen managing tabs - and I've tried several. Congrats!

awesome add-on with good information and howto make it better

PRO--
Vertical tabs provided by Tree Style Tabs is a wonderful idea. Despite Mozilla's rush to Quantum, at least Piror has provided a version that works (after a fashion) with FF Quantum

CONS--
1. Many of us who use Tree Style Tabs regularly have a great need for its companion extension, "Open Link in New (Tree Style) Tab". OLNT is available for pre-Quantum FF, and works fine, but is not available (yet?) for Quantum.

2. Under pre-Quantum FF, we could create a bookmark of all open TST tabs. Under Quantum, however, we are told Quantum has a bug which prevents our creating a bookmark without prior FF permissions, and are told to use the TST toolbar button to grant ourselves permission to create bookmarks. However, the toolbar button has no explicit control to grant permission, so we still cannot create a FF bookmark of TST vertical tabs.

3. Many of us expected that when we installed the Quantum version of TST, the top-most, horizontal tab bar would disappear, as it always did in pre-Quantum FF. But no-- the horizontal tab bar remains, for some inexplicable reason.

非常不错的主意！！！！当标签页多起来时，看着原生的标签管理 你会忘了你到底打开了些什么，一团糟。现在一切都好起来了。

This extension is the main reason I use Firefox.

One request: I wish settings/custom CSS would use Firefox Sync.

This extension is one of the reason I keep using Firefox. Makes it easy to use hundreds of tabs. Has all the functions I need and is still in very active development.

Great for organizing tabs. Now this extension and the ones like session managers and tab groups (Panorama) need to integrate with it.

A necessary extension to Firefox. The main reason I use Firefox is for vertical tabs, and this works very very well.

I had a recent problem with TST not initializing, but removing and re-adding the extension fix me right up.

I can finally organize links in a sane way. Bookmarks are too permanent, while just leaving a pile of tabs is too unstructured. This works.

Very helpful with 100+ tabs across multiple windows as it opens a sidebar which is specific to each.

Put it together with Auto Tab Discard and boom!

This has changed my life. I am able to stay on top of tabs much better when I can see them this way. After Firefo Quantum came out, my preferred tree-style tabs add-on no longer worked, and I thought I was banished to an endless sea of horizontal tabs forever...thanks for your work on this!

Lovely extension. I expect to see more improvements in the future. Would be nice if it used ideas from https://chrome.google.com/webstore/detail/quick-tabs/jnjfeinjfmenlddahdjdmgpbokiacbbb?hl=en

An essential extension if you have about 200 tabs open, like me :-)
Thank you so much for your hard work!

you have the best wiki for tree tabs

tabhideにもいち早く対応し、グループのスイッチができる数少ない縦型タブアドオンだと思います。
せっかくtabhideに対応しているので、タブのコンテキストメニューに「Simple Tab Groups」のグループ移動のメニューが出てほしいと思いました。
上部のタブバーを隠すと他のアドオンのコンテキストメニューが開かないので、タブグループの移動ができないのです。