A fellow developer pointed me to an lecture from Standford University's CS department, available on the internet.
It teaches coding in Swift, SwiftUI and only requires a general understanding of coding as a prerequisite. All the swifty things are explained in a very approachable way. It may be of interest for FM developers who are just curious about how that Swift stuff works.
Thank You for the link!
Even more interesting would be something about developing for macOS (with SwiftUI) - at least for me, getting tired to find (search...) out all the differences between iOS and macOS...
I will also suggest the following site which is free to learn UIKit and SwiftUI.
[https://www.hackingwithswift.com/](Hacking with swift)
mostly - if not all - for iOS
Swiftfull Thinking is also a very good source, free
Keep in mind that some methods will not work under macOS if just copied from iOS (ie some buttons, need more params..j
It helps getting a good understanding what Swift is and what it's capabilities are. Once you got there it is fairly easy to develop macOS apps, too. Most of the UI code is common to iOS and macOS, the rest you'll get sorted out. The big picture is getting a basic understanding and command of Swift for a start.