I've been using Tabby Cat [1] for a few years now and under no circumstance will I replace my cute cats with a productivity tool.
[1] https://chromewebstore.google.com/detail/tabby-cat/mefhakmgc...
Neat! I use the Tabagotchi extension. There's a little monster that grows and then dies when you have too many tabs open. Helps me keep down the tab-clutter.
https://addons.mozilla.org/en-US/firefox/addon/tabagotchi-ne...