There’s no YouTube app in the current development version of iOS and this is probably also for the subsequent iOS 6. Now one of course wonders why this is so. Officially the license has expired and it has therefore abolished it. Others say that it is because Apple is trying to separate with the largest competitor Android who is supported by Google.
Still, for many iPhone, iPod touch, and iPad owners, this “innovation” will not negatively impact it, because YouTube has done a great job at the mobile site. It loads faster and runs as smooth as liquid, so many are already changed. In addition, the video portal is already in your own app, you can download then at the Apple store. No reason to bemoan the current app.