Bookmark OS - Bookmark OS is like Mac or Windows optimized for bookmarks.
BookmarkSheet - Your bookmarks in Google Sheets
Bookmark It - Create awesome notes on YouTube videos
Raindrop.io - All your articles, photos, video & content from web & apps in one place.
Siimpl Bookmarking - Start collecting and organizing what interests you
Stationian - Stationian bookmark manager intelligently analyzes the websites you saved and determines the best way to present them without needing to go to the website.