Nice better than Tree Style tab add-on.
But there is a small problem when opening browser for the first time, it freezes the whole firefox, can't choose tabs & need to restart it couple of times so it can load normally. Hope you will fix it soon.

Muy Buena extencion

Лучшая панель вкладок которую я видел.

The addon is excellent, but I would like to add the function of automatic collapsing of grouped tabs over time.
Now you have to do it every time in order to free up your free space.

This should be the second add-on that you install after uBlock.

The customizability is quite intimidating, but once you get it dialed in it's a browser experience that is unmatched.

Huge thank you to the author for creating this, and for putting the source on GitHub. People like you are the reason that open source works.

It's usefull

Better than Tree Style tab but...how to hide horizontal tabs?