Block Together - A useful tool which helps you block trolls on Twitter.
Tweeten 2 - A powerful Twitter client based on TweetDeck.
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.
Better TweetDeck - Make TweetDeck even better with emojis, thumbnails and more
CleanSpeak - Keep inappropriate content and trolls out of your community
Refined Twitter - A browser extension that improves the Twitter experience