On the eve of watchOS 6's distribution to Apple Watch owners everywhere, Apple has warned developers for the Apple Watch to get on board with the latest SDK. After March 2020, all new apps will need to be built using watchOS 6 SDK and must support Apple Watch Series 4 or later.
Apple's dictum is not surprising. The company wishes for all customers, whether that be owners of the Apple Watch, iPhone, or iPad, to have the same experience. This is reinforced by Apple's update strategy, which is to distribute platform-wide system updates to all devices at once.
Considering the feature set of watchOS 6, developers should want to hop on sooner rather than later. Here's why.
For the first time, developers can create wholly stand-alone apps for the Apple Watch. Thanks to watchOS 6, app writers no longer need to anchor their watch app to a phone-side app. For many, this could halve the effort behind developing apps for Apple's wearable.
Apple explains that watchOS projects can be organized in one of two ways: watch-only app, or watchOS app with a companion iOS app. Apple suggests the former when developers want or need to create experiences only for the Watch, and the latter when developers want to enhance the Watch app with a related phone-based app.
Importantly, independent apps don't need the companion app to work properly. This gives developers and end-users more freedom to leave their iPhones at home. In watchOS 5 and earlier, all watchOS apps are dependent on a companion iOS app.
Moreover, Apple Watch owners can browse for, purchase, and download independent watchOS apps directly from the App Store on the Apple Watch. That's something every developer should get excited about.
Once developers pick which type of app they are going to create, they can take advantage of tools from Apple to optimize for the latest watches. For example, SwiftUI and new APIs are available to help hook into Apple Watch hardware features. The watchOS 6 SDK also provides access to Core ML and the Neural Engine in the Apple Watch Series 4 and 5, which can perform on-device analysis. Other features include support for streaming audio for music apps and extended runtime for session-based use.
You can download the latest watchOS SDKs and betas here.