For blocking out tweets on certain topics
shush! lets you avoid tweets on certain subjects without blocking, muting, or unfollowing people.
Say your friend always talks about new Game of Thrones episodes as soon as they come out even though you don't get a chance to watch them for a few days. Rather than unfollow that friend--or avoid Twitter entirely--just add "Game of Thrones" to the list of blocked words. Now any tweet with those words will be hidden.
(Note: Hidden tweets will tell you why they are hidden; and they are not removed--you can still peek at the tweet by mousing over it or click on the tweet to interact with it normally.)
(Second note: The blocking method is very literal. If you write "Game of Thrones" as a blocked word, tweets with that exact spelling will be blocked.)
shush! has a persistent memory, so if you want a word or phrase blocked for a while, it will do that for you. You can even sign in to your account on a different computer that has shush! installed and shush! will remember your settings.
I made shush! as a student project at @MakerSquare; if it has any errors or if you can think of ways that would improve your user experience, please get in touch with me on Twitter at @inCatastrophe.