I have a question.
How can I make my app available not only on any iPhone with any iOS version, on other devices too for downloading and then using?
You asked this question here and I responded
In this topic I ask not only about iOS Devices!
Make a web app and have the user access it through their browser. That’s the only way to get an app on every version of iOS and other devices as well.
If you are asking about making your iOS app an Android app you might want to do a web search for the answer to your question. The first answer I came up with was about using Kotlin to make your Swift App into an Android App. I’ve never done it myself but it looks like it will take some tweaking to get it to work exactly right.