@jakep That option is disabled for meEDIT: More interesting is that is seems to be enabled by default for the nightly builds with all the options enabled.EDIT 2: Found the saved groups under the drop-down menu arrow on the right of the tabs
@trotosare you right-clicking the tab itself? That is where the option showed up for me.@callnickmaybe Mozilla wants to do more internal testing and fine-tuning before making it an enabled-by-default feature
It's there, but disabled by default. To enable it, go to about:config and search for "browser.tabs.groups.enabled" and click the double-arrow button to mark "true." After it's been enabled, you can right-click your tabs and add them to groups
