Absolutely hideous since Firefox 57.0 launched.
It's probably something rather fundamental that has changed in Firefox that means I'm not stuck with the default tab style AS WELL as the tree style tab.

I think Piro has either reached obsolescence or lost sight of the original idea.
I wanted less screen wastage, now I've got a button, and the tree tabs have a header, *and* I've got the tabs at the top.

If I can't get rid of the regular tab style, I will just have to get used to it.

Real shame - I've been using Tree Style tabs for years, and you've been perfect - but now it's much too ugly to use.

I'm sorry. :(

Firefoxが57になりこのアドオンが最新版に更新された結果、ブックマークサイドバーにタブツリーが統合されてしまい、大変不便になりました。自分の使い方として左サイドバーにブックマークを表示し、右側にツリー型タブというスタイルでしたので、現状の仕様に困っています。もし、作者様にもどうにもならない仕様の更新でしたら申し訳ありません。

I installed it because I read it could place my Tabs back to the Bottom, but it can't .
Don't know if it has any other useful features ( seems to be too Complex for a "Normal" User )

I'd like to try this, but can't... attempting install tells me that my FF 57 is really 48, and refuses. This is on 64-bit Debian, in case that matters.

What's with the permissions requirement?

После внезапного краха всё дерево было утрачено. Теперь нужно создавать с нуля. С Tab Groups такого никогда небыло.

Cannot remove tab bar on top anymore.

Requires access to ALL data from websites, read and modify bookmarks, and use notifications... I cannot remotely see why those permissions could be possibly needed...

Not working in firefox android version 57 (2017.11.15)

Closing some tabs causes others to be closed as well, most likely only tabs on right side of the closed one.