YouTube app for download in the iTunes App Store.
"The new app is built by YouTube engineers, to give our iPhone and iPod Touch users the best mobile experience," said Andrey Doronichev, head of YouTube mobile, in a blog post Tuesday.
Doronichev added that an iPad-optimized version of the app is also being developed.
The discontinued YouTube app, created by Apple to display YouTube content and present on iPhones as a pre-installed app since June 2007, will be absent from iOS 6, the forthcoming version of Apple's mobile operating system. Apple has attributed the change to the conclusion of a licensing agreement between the two companies.
Though neither Apple nor Google has commented on why the licensing agreement was not renewed, it's widely believed that Apple's patent war against Android made the deal untenable.
Apple has also been working to distance itself from other Google services, most notably Google Maps. iOS 6, expected to be available by the end of the month, makes the iPhone's Maps app reliant on Apple map data rather than Google map data.
Apple is expected to introduce the iPhone 5, which should ship with iOS 6, on Wednesday at a media event in San Francisco, Calif.
The new YouTube app turns out to be much better than the old one. Its user interface is more sophisticated, having obviously borrowed some of the design conventions seen in Google's Google+ app and Chrome for iOS. Panels now slide with an animated bounce. The search icon has been moved to the top right-hand corner of the app; previously, search was accessible only through a menu tab on the bottom. The app also adds support for voice search.
There's a new share sheet, which allows users to share videos via Google+, Twitter, Facebook, Email, SMS, or to their device's clipboard.
Google's YouTube app also will display YouTube ads, unlike the older Apple-design version. As a result, users will be able to view videos that were previously blocked because owners of that content didn't want their videos to be shown without the compensation of ad revenue.