IconRazor let's you quickly create icon assets for your iOS, macOS, tvOS, watchOS and carOS apps: Just drag your high resolution artwork (preferably, a PNG file at 1024x1024) into the app's window, chose the target platforms, export the results, and you're set.
Ideally, you would want to have your designer fine-tune each icon size by hand, for best visual results in terms of detail pixel alignment, etc.
But if you just want to quickly fill all the "buckets" in the AppIcon item of your asset catalogue, this simple tool can help you.
* Creating appIcons for all platforms(iOS, macOS, tvOS, watchOS and carOS)
* Creating LaunchScreens for iOS for landscape & portrait modes
* Creating icon sets in @1x, @2x and @3x sizes.