Java Desktop App to Android

I have a finished Java desktop program built with standard buttons, menus and multiple screens. I now need it running on phones and tablets as a signed APK. The goal is a faithful port: every existing screen, button and workflow must appear and behave on Android exactly the way it does on the desktop version, with no feature left behind and no radical redesign.

You can reuse or adapt the current Java code base, but the final result must compile cleanly in Android Studio and target recent Android API levels. Any desktop-only calls (file paths, windowing, threading, etc.) will need Android-specific replacements, yet the outward behaviour must stay identical.

Deliverables
• Complete Android Studio project with clearly organised source, resources and gradle files.
• Release-ready APK plus a debug build for testing.
• Short build & deployment guide so I can reproduce the APK locally.

Acceptance criteria
• All original features and screens present; layout variance on common phone resolutions no greater than ±5 %.
• Smooth navigation and stable performance with no crashes across Android 9+.
• App clears Play Console pre-launch testing without blocking issues.

Please let me know your proposed approach, any libraries you’d introduce (Jetpack, Material components, etc.), and an estimated timeline so we can move forward quickly.