Twitter for iOS and Android now includes "mute" feature
The new "mute" feature allows you to exclude tweets and retweets from your home timeline for those Twitter users less important to you. In addition, you won't receive a push or SMS notification when the "muted" user sends out a message. The person you mute will still be able to reply to, "fave", or retweet one of your tweets. The activity just won't show up in your timeline.
And since Twitter is all about not hurting others' feelings, the person you "mute" will never know that you did this to him (or her), unless you decide to tell. And you can always un-"mute" that same person when the tweets from him or her become more important to you.
To mute someone from a tweet, tap on more and click on mute@username. To mute someone from their profile page (would that be crueler?) click on the gear icon and then click mute@username.
source: Twitter via Gizmodo