Moderate - Identify, mute, and block trolls in your Twitter feed

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.

Blockistan - Blocklists for Twitter. Auto block thousands of users at once

Boyfairy - Your opportunity to educate right before you block someone.

Block Together - A useful tool which helps you block trolls on Twitter.