Update: Mark Gurman breaks down what it all means here

Apple today announced a few leadership changes including a new COO and changes to App Store leadership. Jeff Williams, previously Senior Vice President Operations, is officially being promoted to Chief Operating Officer which is CEO Tim Cook’s old title. Williams, notably, has been heavily involved in the Apple Watch team as well as the open source ResearchKit initiative.

Phil Schiller, Apple’s Worldwide Marketing SVP, will add to his responsibilities the task of overseeing all the App Store leadership. The App Store change notably follows discontent from developers that the iPhone App Store has seen more focus than the Mac App Store, which key developers have left in recent months. The move officially acknowledges Schiller’s role as the face of the App Store going forward.

These App Stores now include the iPhone and iPad App Store on iOS, Apple Watch App Store for watchOS, Apple TV App Store for tvOS, and Mac App Store on OS X.

Johny Srouji, previously Vice President Hardware Technologies, is being promoted to the executive level as SVP of Hardware Technologies. And Tor Myhren will join the company early next year to become VP of Marketing Communications.

Today’s year-end leadership changes are already reflected on Apple’s leadership page, and follow the shift earlier this year that put Jony Ive in the role of Chief Design Officer and named two lieutenants, Richard Howarth and Alan Dye.

From Apple.com:

Apple Names Jeff Williams Chief Operating Officer

Johny Srouji Named to Executive Team; Phil Schiller Adds Ecosystem Responsibilities

Tor Myhren Joins Apple

CUPERTINO, California — December 17, 2015 — Apple® today announced that Jeff Williams has been named chief operating officer and Johny Srouji is joining Apple’s executive team as senior vice president for Hardware Technologies. Phil Schiller, senior vice president of Worldwide Marketing, will expand his role to include leadership of the revolutionary App Store® across all Apple platforms. Apple also announced that Tor Myhren will join Apple in the first calendar quarter of 2016 as vice president of Marketing Communications, reporting to CEO Tim Cook.

“We are fortunate to have incredible depth and breadth of talent across Apple’s executive team. As we come to the end of the year, we’re recognizing the contributions already being made by two key executives,” said Tim Cook, Apple’s CEO. “Jeff is hands-down the best operations executive I’ve ever worked with, and Johny’s team delivers world-class silicon designs which enable new innovations in our products year after year.”

Cook continued, “In addition, Phil is taking on new responsibilities for advancing our ecosystem, led by the App Store, which has grown from a single, groundbreaking iOS store into four powerful platforms and an increasingly important part of our business. And I’m incredibly happy to welcome Tor Myhren, who will bring his creative talents to our advertising and marcom functions.”

Jeff joined Apple in 1998 as head of worldwide procurement and in 2004 he was named vice president of Operations. Since 2010 he has overseen Apple’s entire supply chain, service and support, and the social responsibility initiatives which protect more than one million workers worldwide. Jeff played a key role in Apple’s entry into the mobile phone market with the launch of iPhone®, and he continues to supervise development of Apple’s first wearable product, Apple Watch®.

In nearly eight years at Apple as vice president of Hardware Technologies, Johny Srouji has built one of the world’s strongest and most innovative teams of silicon and technology engineers, overseeing breakthrough custom silicon and hardware technologies including batteries, application processors, storage controllers, sensors silicon, display silicon and other chipsets across Apple’s entire product line. Educated at Technion, Israel’s Institute of Technology, Johny joined Apple in 2008 to lead development of the A4, the first Apple-designed system on a chip.

With added responsibility for the App Store, Phil Schiller will focus on strategies to extend the ecosystem Apple customers have come to love when using their iPhone, iPad®, Mac®, Apple Watch and Apple TV®. Phil now leads nearly all developer-related functions at Apple, in addition to his other marketing responsibilities including Worldwide Product Marketing, international marketing, education and business marketing. More than 11 million developers around the world create apps for Apple’s four software platforms — iOS, OS X®, watchOS™ and tvOS™ — as well as compatible hardware and other accessories, and customers have downloaded more than 100 billion apps across those platforms.

Tor Myhren joins Apple from Grey Group, where he has served as chief creative officer and president of Grey New York. Under his leadership, Grey was named Adweek’s Global Agency of the Year for both 2013 and 2015. As vice president of Marketing Communications at Apple, Tor will be responsible for Apple’s advertising efforts and will lead an award-winning team that spans a broad range of creative disciplines from video, motion graphics and interactive web design to packaging and retail store displays.

Tor will succeed Hiroki Asai, who earlier announced plans to retire after 18 years in graphic design and marketing communications roles at Apple.

Apple revolutionized personal technology with the introduction of the Macintosh in 1984. Today, Apple leads the world in innovation with iPhone, iPad, Mac, Apple Watch and Apple TV. Apple’s four software platforms — iOS, OS X, watchOS and tvOS — provide seamless experiences across all Apple devices and empower people with breakthrough services including the App Store, Apple Music, Apple Pay and iCloud. Apple’s 100,000 employees are dedicated to making the best products on earth, and to leaving the world better than we found it.

Press Contacts: Kristin Huguet Apple khuguet@apple.com (408) 974-2414 Apple, App Store, iPhone, Apple Watch, iPad, Mac, Apple TV, OS X , watchOS, tvOS and the Apple logo are trademarks of Apple. Other company and product names may be trademarks of their respective owners.