In an attempt to make it easier to design apps for the Apple Watch and Mac, Apple has updated its Human Interface Guidelines with new templates for the new operating system versions it will release in the fall.

Apple has added a full set of AppKit UI elements, in order to help developers design apps for Mac using Sketch or Photoshop, while also adding several new UI elements for Apple Watch apps and watch face templates. The update was released ahead of this fall's release of Mac OS Mojave.

Apple had released similar guidelines for iOS developers, also with Photoshop and Sketch, in January of 2017.

For macOS, the guidelines emphasize four themes, which Apple says "differentiate macOS apps from iOS, tvOS, and watchOS apps." The apps are meant to be flexible, expansive, capable and focused.

"Macs are extremely capable in terms of hardware and software. Apps can harness this power to offer an extensive range of features and workflows that meet a wide variety of simple, advanced, and niche user needs," the macOS guidelines say.

The resources have been made available for download from Apple's developer page.

For watchOS, Apple has also released Sketch and Photoshop guides, as well as layout specifications, app templates, Apple Watch bezels and more. Those can be downloaded from here as well.

The main design principles for Apple Watch include lightweight interactions, holistic design and personal communications.