AR browsers work by using GPS to detect the user’s current location while the compass detects the direction the device is facing. With the user’s current location and their direction known, the nearby POIs can be displayed in the camera window. As the user moves the mobile device around, the accelerometer detects the elevation while the compass continues to detects the direction the user is currently facing. This combination enables the application to use the map data to build the AR view. In Figure 3-1, you can see POIs from the Qype world for the Wikitude browser shown on a map, with the map indicating their actual location. In Figure 3-2 the same POIs are drawn in the AR browser window, providing a visual indication on their locations.