Now the examples of metal-cpp are target on desktop and using AppKit which is not supported on iOS. Is there any tips for developing with metal-cpp on mobile device?
The link above is helpful.
... and three years later ...
Check out game porting example code.
Here you'll find:
Learn from game porting code examples
These examples are based on our learnings from working with developers that simultaneously shipped their high-end games on Mac, iPad, and iPhone. You’ll learn essential steps, like how to convert your Windows display, input, and audio APIs and how to build your shaders once and deploy everywhere.