Andrey Doronichev, head of YouTube mobile:
For all you diehard YouTube fans out there who can’t get enough YouTube on your mobile, we’ve got some great news: starting today, you can download the official YouTube app for iPhone and iPod touch from the App Store, bringing you more of the videos you love and more ways to share them with the people you care about.
The YouTube app that has been built into iOS since the original iPhone is not present in iOS 6, so this announcement was well-timed. Looks like a good app, with a Google’s iOS UI style. Given that this new YouTube app from Google shows ads, and Apple’s old YouTube app did not, my hunch is that the decision to part ways was mutual.