Tab Stash - Tab Stash is a browser extension that helps you keep your tabs straight, saved, and restore them later.
Tabs Outliner - Next Generation Session, Windows, Tabs Manager and a TooManyTabs Solution That Really Works.
Tabli - A simple, powerful tab manager
Tab Session Manager - Save and restore the state of windows and tabs.
Workona - A better way to work in the browser.
Session Buddy - Manage Your Browser Sessions