Instant USGS Earthquake Lite is a free app offering limited features and alerts related to world earthquakes and NOAA radar updates. The app is part of a Universal Purchase, allowing access to NOAA Alerts across iOS, Watch OS, and Apple TV devices with a single purchase. Earthquakes are color-coded based on magnitude, ranging from red for EQ 4.0 or larger to green for all other EQs. Users can view alerts by date or severity, explore alerts on a map with various map types, and access real-time NOAA radar images. Additionally, the app offers 3D view functionality for a more immersive earthquake alert experience.