[chrismorgan]

Firefox used to have a feature called Panorama built in (if I recall correctly), where you could arrange your tabs into groups and see thumbnails of all your tabs. It would probably answer this sort of purpose quite nicely. Other tab management systems like vertical tabs and tab trees (I use Tree Style Tab) are probably very helpful too.

Just at a very quick glance, https://addons.mozilla.org/en-US/firefox/addon/panorama-tab-... looks like the most popular replacement for that old Firefox feature.

(I don’t mean that it’s an exact replacement, but it’s likely to be more convenient for single-session usage since it’s a tab management solution rather than an extra tool to use.)