One of the most popular features in third-party Twitter apps is the ability to mute people. In fact some apps have the ability to mute hashtags, keywords and other things as well. Which are really useful, especially during WWDC, since we don't care much about Apple. Twitter started testing out a mute feature on their own apps, through the beta. And they are now rolling it out to their respective apps. Which the update should appear on Google Play rather soon, as it usually takes about 2 hours for it to show up in Google Play, so it may take some time. You will be able to mute people, but not hashtags and keywords just yet. Hopefully Twitter has that functionality coming soon.
"In the same way you can turn on device notifications so you never miss a Tweet from your favorite users, you can now mute users you'd like to hear from less. Muting a user on Twitter means their Tweets and Retweets will no longer be visible in your home timeline, and you will no longer receive push or SMS notifications from that user. The muted user will still be able to fave, reply to, and retweet your Tweets; you just won't see any of that activity in your timeline. The muted user will not know that you've muted them, and of course you can unmute at any time. To mute a user from a Tweet on your iOS or Android device or on Twitter for web tap more and then mute @username. To mute someone from their profile page, tap the gear icon on the page and choose mute @username."
As shown in the quote above, it's really easy to mute someone and unmute them. Basically head to their profile page and use the gear icon. It's just that simple. Although there's no central place to see who've you muted. That's something else that needs to be added, I think.