Reviews saying this syncs through Firefox are incorrect - this syncs ONLY through Dropbox. Useless to me, I'll just make a "Read Next" bookmarks folder, FF will sync it for me to all my devices. No need to add yet another extension and slow my browsing to a crawl.

Blows the competition away. This is a really lovely looking app and the "add to read next" icon on the toolbar is really in-keeping with Firefox's own icons, and the reading list side-bar is nice and compact. Nice one!