The App API handles high level App state and events.For example, this API emits events when the app enters and leaves the foreground, handles deeplinks, opens other apps, and manages persisted plugin state.
The Device API exposes internal information about the device, such as the model and operating system version, along with user information such as unique ids.
The Geolocation API provides simple methods for getting and tracking the current position of the device using GPS, along with altitude, heading, and speed information if available.