Most people follow many people to keep connected, but would rather not see every single tweet. Proxlet allows your Block Unwanted Tweets, Apps, Mute but still follower users and filter specific hashtags.
The extension works within Google Chrome & desktop clients such as TweetDeck. Proxlet is also supported on Mobile Clients such as Twitter for iPhone, Twidroyd, & Seesmic for Android.
You can get the extension on their Official Site Here.