Adblock Plus - AdBlock Plus is a browser extension for Firefox, Chrome, Opera, and several other popular browsers that prevents intrusive ads like pop-ups and malicious code from appearing on websites you visit.
Privacy Badger - Privacy Badger blocks spying ads and invisible trackers. How is Privacy Badger different from Disconnect, Adblock Plus, Ghostery, and other blocking extensions?
BlockParty - Real-time voice chat rooms from the creators of turntable.fm
uMatrix - uMatrix: A point-and-click matrix-based firewall, with many privacy-enhancing tools.
Twitter One Click Block - Add a block button for a simple one click blocking.
Ghostery - Privacy tool for transparency and control