BlockParty - Real-time voice chat rooms from the creators of turntable.fm
Secateur - Use Secateur if you want to temporarily or permanently block or mute (or both block and mute) a Twitter account and all its followers.
Moderate - Identify, mute, and block trolls in your Twitter feed
Likers Blocker - Likers Blocker is a browser extension that lets you block all the followers and the people who like a specific tweet on Twitter.
Blockistan - Blocklists for Twitter. Auto block thousands of users at once
Red Block - Red Block is a browser extension that lows you to block users from your Twitter account.