Bookstack is an add-on for the Firefox web browser. Its purpose is to enable high-volume browsing by quickly adding and then viewing/removing bookmarks.
Installation of the latest release is available at AMO: Bookstack.
You may file bugs or submit pull requests for fixes to this github repository (or if you're reading this elsewhere, at Github: Bookstack). Some documentation is available in the repository wiki at Github: Bookstack: wiki.