Google Geofencing API

The Google Geofencing API is a developer API for Android rather than an application, and that distinction decides whether it belongs on your shortlist. It gives an app the ability to define perimeters, called geofences, around areas of interest and receive a notification when the device crosses one. There is no dashboard, no campaign manager and no reporting: everything is built by your own developers against the API. For teams shipping a mobile app, that is exactly right; for a marketing team wanting to run location campaigns, it is not the product.

The problem it addresses is stated plainly. Users often want an app when they are in a specific place, such as an airport or a supermarket, but they have to remember to open it and find the right function while they are there. Geofencing inverts that, letting the app reach the user at the moment the location becomes relevant. The vendor's example is an airline app defining a geofence around an airport when a reservation is near boarding time, so crossing the perimeter surfaces a notification leading straight to the boarding pass.

The implementation model is worth understanding before committing. A geofence object is created by setting latitude, longitude, radius, duration and transition types, where transition types define the triggering events such as entering or exiting. Geofences are collected into a geofencing request, which is submitted to a geofencing client along with a PendingIntent describing how events should be delivered. Events arrive at an IntentService in the app, which the vendor highlights specifically because it removes the need to run a background service: the service is invoked only when there is relevant information. Location detection is described as intelligently using device sensors to stay battery-efficient, which is the constraint that historically made geofencing impractical on mobile. Documentation is available in more than twenty languages.