When I'm developing an Android app, how should I port to Swift?
Implementation in Swift
No simple way.
But, if your app is complex enough as found in App Store, it would be a bunch of work and study.
If you start developing apps for both Android and Apple from now, consider using so-called hybrid frameworks.
But this is not a good place to discuss third party frameworks.
Analyze the functionalities of your Android app
Re-design your app considering what sort of frameworks are provided to realize such functionalities in Apple's platform
Implement the re-designed app in Swift
But, if your app is complex enough as found in App Store, it would be a bunch of work and study.
If you start developing apps for both Android and Apple from now, consider using so-called hybrid frameworks.
But this is not a good place to discuss third party frameworks.
The question is not only porting from Java or other to Swift, but porting from Android to iOS.
That may require significant rewriting.
There are cross platform tools. If you google for "multi platform ios android development", you will find plenty of references.
Personally, I do not use them. And if your code is already written, you should have to port to this multi platform environment.
My best advice : use the Android version as the spec of your app and develop a brand new code for iOS to take all benefits of the OS and API.
Good luck.
That may require significant rewriting.
There are cross platform tools. If you google for "multi platform ios android development", you will find plenty of references.
Personally, I do not use them. And if your code is already written, you should have to port to this multi platform environment.
My best advice : use the Android version as the spec of your app and develop a brand new code for iOS to take all benefits of the OS and API.
Good luck.