If you're a Twitter user, you need to be using Tweetbot 3.0. It isn't just the best Twitter client, which it is by a long shot, it is my favorite iPhone app period. The iPad version is still on 2.0 with the pre-iOS 7 design, and even that is a league above most other Twitter clients. When I did a trial switch to Android, the lack of Tweetbot was among my top complaints, I found myself not wanting to use Twitter anywhere near as much without it.
It is usually $4.99, but it is on sale for $2.99 right now. It is a simple gift idea for the holidays that I cannot recommend highly enough. I have no affiliation, I'm making no money on this. It is simply that good of an app that I felt compelled to spread the word.