TweepsBook - A better bookmarking tool for power Twitter users that you can use to filter, organize and bookmark tweets on your liking.
Raindrop.io - All your articles, photos, video & content from web & apps in one place.
Bookmark OS - Bookmark OS is like Mac or Windows optimized for bookmarks.
Tweetflick - Save, organize & find Tweets to get the most out of Twitter
Lookmark - Track updates from the apps you've bookmarked on iTunes
Siimpl Bookmarking - Start collecting and organizing what interests you