bozobit by Leo

"One thing Twitter needs: a way to remind you that you have judged a person's opinions to be garbage and not worth spending time to examine them other than blocking/muting. Just have their tweet show up in grey or something." -- @Subb4k on Twitter

bozobit lets you flag users as bozos and not work taking seriously. Click "Mark as bozo" in the action menu to mark all tweets from the user.