The app is a WebView wrapper around the WeatherStar 4000+ web emulator by netbymatt. It bundles everything locally and injects some JavaScript on top for kiosk features like location detection, settings, and music.
Location chains through GPS first, then falls back to IP geolocation if that's not available. Settings are accessed with a long press and get saved between sessions.
The music comes from the Weatherscan Complete Collection on Archive.org.