Tabalanche was an extension for Google Chrome (and, tentatively, Mozilla Firefox) that helped you focus on what you're doing, by letting you save all the extra tabs you have open to a list - so you could revisit them later, once you really needed them.
Unfortunately, it was broken on Jul 24th 2025, when Google forcibly disabled all extensions still operating the decade-old generation of programming model that Tabalanche was designed to function within. A rewrite to accomodate the changes necessary to get Tabalanche working again is currently under way: subscribe to this GitHub issue for updates on that rewrite's progress.