Twitter for Mac
The Mac app finally gets the Connect tab which includes interactions such as favourites and retweets along with your mentions.
Android, iPhone, iPad and mobile.twitter.com
These apps will also get improvements to search results. Now when you search for people on Twitter you may see an expanded user result that show sa full bio. Twitter says this "makes it easier and faster to find and learn more about the accounts you’re looking for." If you then swipe the bio preview to the left it will show similar accounts. Additionally a new indicator in search results will show when there are new Tweets related to your search.
Twitter for iPhone
You can now reply to tweets easier with the built-in Tweet composer that appears when you tap to see details. It’s also now much easier to find accounts to follow with a brand new people button on the nav bar, just like the Android version.
Source: Twitter Blog