- This app displays your speed and acceleration on your cars windshield. - The app supports both mph and km/h units - To project the the information on your device on the windshield simply place your device on the dashboard of your car. You can secure the device on the dashboard by a variety of solutions that are commercially available. - To project on the windshield, make sure that you select the "mirrored" display in the app so that the reflection on the windshield is displayed correctly.