Head-Up Display User Guide
The Head-Up Display application transforms your phone into a portable head-up display that can be used in your car, but also in other means of transport as the picture below shows:
The application uses the GPS signal received from your phone. When your phone does not yet receive GPS a blinking question mark is shown. The display is intentionally mirrored as the phone needs to be placed on your car dashboard below your windshield. When the phone display is reflected back into your line of sight the speed displayed can be read correctly.
The only option that can be set is the measure used to denote speed. Default is imperial miles per hour, and you can switch to kilometer per hour.