Apple has announced that iOS 9 is the fastest adopted software update ever, with more than 50% of active devices running the latest version as measured by the App Store on September 19.

“Customer response to the iPhone 6s and iPhone 6s Plus has been incredibly positive, we can't wait to get our most advanced iPhones ever into customers’ hands starting this Friday,” said Philip Schiller, Apple’s senior vice president of Worldwide Marketing. “iOS 9 is also off to an amazing start, on pace to be downloaded by more users than any other software release in Apple’s history.”

Apple marketing chief Phil Schiller says that iOS 9 is on pace to be downloaded by more users than any other iOS version ever released. He also said that response to the iPhone 6s and iPhone 6s Plus has been "incredibly positive," but no specific sales figures were disclosed.

iPhone 6s and iPhone 6s Plus launch on September 25 in the U.S., Australia, Canada, China, France, Germany, Hong Kong, Japan, New Zealand, Puerto Rico, Singapore and the U.K. Last week, Apple said pre-orders for the new iPhones are "on pace to beat" last year's record-breaking 10 million iPhone 6 and iPhone 6 Plus launch weekend.