Symgi - Symgi - New minimal and pure bookmark site. Open multiple or singular links from bookmark groups.

OneTab - Whenever you find yourself with too many tabs, click the OneTab icon to convert all of your tabs into a list. When you need to access the tabs again, you can either restore them individually or all at once.

Dustman - Firefox extension to close unused tabs.

Workona - A better way to work in the browser.

Tab Wrangler - Automatically closes inactive browser tabs

Session Buddy - Manage Your Browser Sessions