The original deal between Apple and Google on the YouTube app helped remake video for the mobile world, as the iPhone's lack of support for Adobe Flash meant YouTube's catalog had to be re-formatted to work in HTML5. The iPhone's popularity helped make MP4 format the standard format for mobile video. Over the years, it became less important for Apple to have a dedicated app for finding videos that would play on its phone.
At the same time, the Apple-Google relationship has soured considerably since the launch of the first iPhone. Apple co-founder Steve Jobs took Google's development of its own mobile operating system, Android, as a great affront -- and an infringement on Apple's intellectual property. Patent lawsuits are now playing out around the world, and Apple has made a series of moves this year to push Google out of its operating system.
At its Worldwide Developer Conference, Apple showcased a new maps application that will replace the Google-powered app now in use on iOS devices. Removing YouTube from the list of pre-installed apps marked the next step.
But for Google, the YouTube break could represent a significant revenue opportunity. The company says its users watch 1 billion videos a day on mobile devices; enabling ads on their iOS app will help the company reach a large new audience.