In iOS 6, Apple removed the official YouTube app which, in turn, was followed by a release of Google's official YouTube app for iOS. But Google's app is not the only new YouTube app for iOS. Tube+ ($0.99) is a great-looking YouTube app that does a few things that Google's app does not.
For one, you can download/cache videos of your choice for offline viewing — a feature that is especially handy if you have a lower data cap. The search is also much faster than Google's own app. Oh, and Tube+'s icon is much nicer than Google's. If you'd like to learn more about Tube+, MacStories has a great little review.