Apple’s WatchOS 10 gets new APIs and designs to build next-gen watch apps

Apple’s WatchOS 10, the latest software that will power Apple Watch, will be available to the public this fall. Along with new features such as redesigned apps to use the entire display, a new Smart Stack with glanceable widgets, and Workout Mirroring on the iPhone, Apple has released a flurry of new APIs in the WatchOS 10 SDK to help developers tap into the new capabilities announced at WWDC 2023.

Also: Apple revamps WatchOS with widgets, new fitness and health features, and more 

ZDNET spoke with Apple to learn how this new set of Apple Watch APIs will help developers build the next generation of Apple Watch apps.

“We’re really excited about what we announced in WatchOS 10 will mean for developers,” Eric Charles, Apple Watch Product Marketing, told ZDNET. “What we’re seeing is more space for content and more glanceability so that Apple Watch is really easy to use… and can show complex information in a really simplified manner.”

New Apple Watch APIs

Apple announced a series of new APIs for WatchOS 10, including: 

• Workout Mirroring API — Shows progress from the Workouts app in a live widget on the iPhone
• Custom Workouts API — Allows third-party apps such as Training Peaks to add routines into the Workouts app for the first time
• High Frequency Motion API — Takes advantage of the new advanced sensors in the Apple Watch Series 8 to track metrics to help improve a golf or tennis swing, for example
• Cycling Metrics API — Can now connect to Bluetooth-enabled bikes and sensors to provide much more advanced training data to cyclists

These are optimized for augmenting an exercise routine, but developers can use each API for any purpose they can imagine within any Apple Watch app.

WatchOS developers use HealthKit as a central place to store health and fitness data for their apps. Developers could always write code in HealthKit, but now Apple says developers can access new data and upgrades to SwiftUI, such as vertical pagination and navigation split view.

Developers who already write code in SwiftUI have an advantage, as their apps will be automatically updated when rebuilt with the WatchOS 10 SDK. Developers can easily share code between iOS and WatchOS, which is a productivity bonus.

New design for Apple Watch apps

WatchOS 10 apps will have a new look and feel to encourage improved glanceability for Apple Watch. Apple says almost every app in WatchOS 10 will be redesigned to utilize the entire Apple Watch display to make information more quickly accessible.

One of the biggest interface changes is that when you turn Apple Watch’s digital crown, you now access the Smart Stack, where widgets appear — up to 10 of them. A new design element of WatchOS 10 is that it encourages you to use the Digital Crown to avoid blocking the Watch display with your finger, allowing developers to convey pertinent information from their widget.

According to Apple, three new foundational app layouts will change how Watch users interact with apps: 

• Dial works best for ring-based applications, like workout routines and goal-meeting
• Infographic displays real-time infographics from apps like World Clock
• List allows for quick viewing of text-based apps like Mail and Messages

Also: Apple releases VisionOS SDK, developers can apply for Vision Pro hardware kit

Watch complications, where developers can display valuable data for users to glance at, will be backed by WidgetKit in WatchOS 10, so they can appear in more places. Developers can reuse most of the code for iPhone lock screen widgets for Apple Watch, according to Apple.

Developers interested in creating WatchOS apps can join the Apple Developer Program for $99 a year to access the tools needed to develop, test, and distribute apps for the release of iOS 17, WatchOS 10, iPadOS 17, MacOS Sonoma, and VisionOS.