Twitter Bookmarks - Create shortcuts to your favorite users/tweets on Twitter
TweepsBook - A better bookmarking tool for power Twitter users that you can use to filter, organize and bookmark tweets on your liking.
Tweetflick - Save, organize & find Tweets to get the most out of Twitter
Bookmark OS - Bookmark OS is like Mac or Windows optimized for bookmarks.
TWRL - It's like merging Instagram and Texting into one platform.
Trello Bookmark - Store your bookmarks as Trello Cards