Firefox Tabbed Groups
Firefox tabbed groups are grouping of tabs into groups with a tab bar to manage groups, only the browser tabs in the currently selected group are shown. Actually it is very useful and makes me convenience when browsing using firefox, but when I created tabbed many groups and many pages under each tabbed group, my firefox started getting slower when I switching from one group to another groups, that’s the reason why I uninstalled and no longer use it.