Twitter have just updated their official app, for both Android and iPhone. The new update brings some new features. The major new features is Expanded Tweets.
For example on the official website you were able to watch a YouTube video right in the Twitter timeline, or look at a photo. Now that feature is coming over to Android and iPhone. Some new sites like Kickstarter and Vimeo are also being added. This feature will be rolling out slowly, so you might not see it right away when you start up the app.
Other new feature include being able to follow major events easier now on your phone, improvements to the search function including autocomplete, discover tab now highlights when there are new stories, can tap on avatars to go straight to a person's profile and of course the new Twitter logo being shown off throughout the app.