Tab Stash is way cooler than this. I found Sidebery to be much faster/efficient than most of the tab extensions, but I love that I can group tabs and 'offload'/archive them with Tab Stash. The only thing missing from Tab Stash was the ability to see which tab is playing audio. I installed the Sound Control extension to list tabs playing audio for that.

What's missing from EVERY tab extension is I just want the ability to show tabs in a tree view, like an ASCII art tree. They all do this indented, css-styled BS that doesn't look more compact or better. I just want an ASCII tree.

Anyway, look at Tab Stash for another alternative.