A URL app plays your web player's audio stream like mobile Chrome does, including HLS and MP3/AAC streams over https. The limitation: a plain WebView may pause audio when the app goes to the background or the screen locks, and has no lock-screen controls. For a radio app people listen to with the screen off, use a converter with background audio support or build a native player.
Use an https stream
Many older stream servers use http://ip:8000/stream. Android blocks cleartext traffic, and https pages block http media as mixed content. Put the stream behind https (most hosts offer it, or proxy it).
Autoplay
Like browsers, WebViews block audio until the user interacts. Show a big Play button; don't fight the rule.
Background listening
Whether audio continues with the screen off depends on how the app shell handles its lifecycle. Test it on the converter's APK before you promise it to listeners: start playback, lock the phone, wait two minutes, then switch apps.
Keep the player page light
The player page stays open for hours. Avoid auto-refreshing ads and heavy scripts that drain battery; poll “now playing” every 15–30 seconds, not every second.
FAQ
Can a WebView app play radio in the background?
Only if the app shell supports it; plain WebViews often pause when the app is backgrounded.
Why won't my stream play in the app?
Usually an http stream on an https page or a cleartext block. Serve it over https.