Android-powered devices have sensors that let you provide users with contextual information about their surroundings, including location awareness, motion, position, and qualities of the physical environment.
To provide a much richer, more more context-specific experience for users, use Android APIs that take advantage of the following types of sensors:
- Use GPS to add location awareness to your app with automated location tracking, wrong-side-of-the-street detection, geofencing, activity recognition, and more. 
- Use motion sensors to measure acceleration forces and rotational forces along three axes. This category includes accelerometers, gravity sensors, gyroscopes, and rotational vector sensors. 
- Use position sensors to measure the physical position of a device. This category includes orientation sensors and magnetometers. 
- Use environmental sensors to measure various environmental parameters, such as ambient air temperature and pressure, illumination, and humidity. This category includes barometers, photometers, and thermometers. 
