Back in the fall of 2012, Apple released both the iPhone 5 and iOS 6. It was a normal update with the regular list of improvements, but for some reason, the YouTube app, which had come installed on every previous iPhone, was missing. At the time, many were quick to blame Apple's decision to sever ties with Google, who owns YouTube, but it turns out the decision was made entirely by YouTube.

In a series of tweets shedding light on the ongoings at YouTube in between 2007 and 2012, former YouTube employee Hunter Walk explained YouTube's decision to cut ties with Apple. When Apple first built the iPhone, it approached YouTube to be included in the original iPhone. The only caveat was that the app was to be made entirely by Apple with YouTube's API and additional language.

This agreement ensured that "the 'YouTube of mobile' was YouTube itself.'" The world was shifting toward mobile, but not many saw this coming. It was moves like the one YouTube made that solidified its role in the mobile landscape that has continued to thrive in the years since.

The move greatly benefited Apple as well, as it gave customers another reason to purchase the iPhone in the form of exclusive access to YouTube through the Apple-made app.

By 2012, the agreement between Apple and YouTube had ended and YouTube made the decision "to take back control of our app." The move had nothing to do with the ongoing split between Apple and Google, as YouTube was still running largely independent from Google at the time.

Thus the YouTube app was erased when people updated from iOS 5 to iOS 6 that fall. Hunter points out that people went right away to the App Store and re-installed it. He also reveals it was a gutsy move, calling it "controversial" because not everybody at YouTube agreed with the move. It's not every day you choose to delete your app from millions of devices, but YouTube did just that and it worked out.

A similar decision was made that year on Apple's part to remove Google Maps and replace it with Apple Maps. That did not work out as well.

Hunter Walk's story is quite interesting and worth a read.