These new resources are meant to guide developers in building their apps.
Apple has updated its iOS Human Interface Guidelines with a set of resources that developers can use when building apps for iOS 10. These resources are available as templates both for Photoshop and Sketch.
The Apple UI Design Resources include Photoshop and Sketch templates, and other UI materials for quickly designing iOS apps. The included resources are comprehensive and accurately depict the full range of UIKit controls, views and glyphs available to developers using the iOS SDK. They make it easier to understand how iOS apps are constructed and how to design apps that match the iOS design language. Included icon and glyph production files have been preconfigured to automate asset production using Sketch slices or Adobe Generator for Photoshop CC.
You can download both templates now directly from Apple. The company has also provided a number of videos about these templates, such as an overview of what's included and how they can be used.