Official Twitter app for iOS has been updated to version 6.1, it brings us new options and features

It also introduces easier reply system in which you are allowed to reply with photos.
New updated Twitter will remind you to do @mention of your friends so that more and more people would be able to see it.
You can also reply with a photo using gallery icon when you click on a tweet.

You can download updated Twitter 6.1 from the App Store