AEIconizer
Sketch plugin for automatic scaling of app icon artwork in all needed sizes (for iOS and macOS).
After creating icon in any square sized artboard, select any layer (or nothing if that's the only artboard on page), then run this plugin to generate all of the needed sizes for iOS, watchOS and macOS.
Plugin replaces all generated artboards every time it runs, but it will never delete your original artboard.
You can see it in more detail on Vimeo.
Installation
Download this repository and double click on AEIconizer.sketchplugin file.
done for fun