I’ve been using Sketch 3 recently (after a long hiatus) and a great productivity tip for iOS 9 design is to take advantage of a GUI template. A GUI template has all the UI elements painstakingly recreated in Sketch, to help you supplement your own designs.
Facebook provide an installer for Sketch (DMG) to install the templates with a few clicks. The template comes in @2x resolution.
If you’d like to add these files or any other to the template option it’s as simple as heading to File > New From Template > Reveal in Finder.
This will show you the folder in Finder, simply drag your fresh templates into here. Once added you can quickly create a new Sketch file with all these elements available for you to use in your next iOS design.