BlockParty - Real-time voice chat rooms from the creators of turntable.fm
Red Block - Red Block is a browser extension that lows you to block users from your Twitter account.
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.
FollowerAudit - FollowerAudit is a platform that allows users to check their fake followers and track the follower growth of any Twitter Account.
Twitter One Click Block - Add a block button for a simple one click blocking.
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.