1. Get the add-on
You can use the site without it but it will significantly improve the experience. By now only firefox is available but more browsers will be available. Stay tuned!
2. Click the icon
This automatically list your opened tabs, then you can edit them and add more manually. Use a title to identify the list of links later
3. Save your collection
Store your favorites safely online in a browser independent fashion. Share with the world your selection of the web, and keep updated on other peoples choices