Get it here: https://addons.mozilla.org/en-US/firefox/addon/tabbucket/

• Clone the project.
• Open FireFox type in "about:debugging" in search bar.
• Click "This FireFox"
• Click "Load Temporary Add-on" and a new tab should open.
• Go to the directory where you cloned the project. Find the "manifest.json" file.
• Click the "manifest.json" file
• Click "Open"

This extension lets users save all current tabs for later and exit. The links to the current tabs will be saved in local storage and will be available to reference the next time you open the extension.