First, I do view any non-JVM/Kotlin/Java apps to be non-native to Android, but might be mistaken about how inferior it is. People do a lot of JavaScript apps, I’m told. There’s also Kivy for Python Android apps, so Julia could do similar. [Note, JavaCall.jl works for JVM, except on Android, its JVM is different.]
I pretty much ruled out Julia as good for Android (at least for now, while it CAN run there in some sense).
It’s because it’s easier to call a non-garbage collected language. I overlooked Swift is such as thing.
I do see outdated (and only worked on macOS): https://github.com/JuliaInterop/ObjectiveC.jl
People avoid Objective-C by now, but can you still do all iOS apps with it? Would it be helpful to resurrect that package?
Swift apps can be cross-platform to Android.
Kotlin apps can be cross-platform to iOS. What would be the preferred way? I would sure choose Kotlin, if only thinking of Android.