Bookmark OS - Bookmark OS is like Mac or Windows optimized for bookmarks.
Zave - Save and share your favourite & most visited websites
Raindrop.io - All your articles, photos, video & content from web & apps in one place.
Thieve - A curated list of the best products on AliExpress
Twitter Bookmarks - Create shortcuts to your favorite users/tweets on Twitter
Canopy.co - Find great Amazon products through a community curated database.