Tabs Outliner - Next Generation Session, Windows, Tabs Manager and a TooManyTabs Solution That Really Works.
Tab Utilities - Tab Utilities is an ultimate tab solution for all kind of users who want to manage their tab, create multiple session and search for new tabs, etc.
Tree Style Tab - Tree Style Tab is an all-in-one Firefox extension that provides ability in order to operate tabs as a tree.
Tab Tally - Firefox add-on, displays how many tabs are open.
Session Buddy - Manage Your Browser Sessions
Adguard AdBlocker - Adguard AdBlocker browser extension, see review on Medium.