There are so many of these topics, and I’ve yet to get a clear understanding an answer. People keep suggesting scale but scale makes the UI to small for mobile users. Take Big Games’ games for a example, they’re able to size UI big enough for mobile users and properly size it for desktop users. Here are some solutions I’ve tried and their effects:
Scale works for desktop, but makes the UI to small for mobile users
Offset makes the UI to big for mobile users
UIAspectRatio does it’s job and keeps the UI proportionate but doesn’t scale it to user friendly sizes
Combining size and offset kind of works, but isn’t optimized for all devices
The easy way: make two versions of your UI- use collectionservice or some other management system for your code, don’t hardcode each UI instance.
The hard way is that you can use UIScale, generic “one-size-fits-all” UI, and a whole lot of UI Constraints to make platform-friendly UI. The problem with this is it adds a huge amount of time to your design process and will never perfectly fit the needs as well as platform-specific UI will.
Notice how for the tiny iphone screen we have to sacrifice the ability to show the social tab by default.
In a perfect world, you use modular UI code and create different versions of your screen spaces for different size screens/platforms. Well planned UI usually takes less work to add onto, in my experience.