How can I turn my web application into an APK without rewriting it?

Looking into Capacitor is another option, although I’ve heard it doesn’t support all native web APIs like the web share feature.

If you're keen on a less restrictive approach, you could consider turning your web app into a Progressive Web App (PWA). This way, users can add it to their home screen without making a full app.

Take a look at pwabuilder.com. It does most of the work for you and helps you publish your app on the app stores easily.

Just a thought—why go through all the trouble of creating an app that may limit your audience? The cheapest way might be to add PWA configuration to your site, so it prompts users to add it as a shortcut instead.

You might want to check out Trusted Web Activities (TWA). It's Google's recommended method for wrapping a web app into an Android package, and it performs better than a typical WebView—making it feel more like a native app.