You will need to grant the DMI access to your phone's GPS signal and on IOS the accelerometers as well to detect device movement. No locations are saved, it only measures real time movement while this page is open. To use the DMI tool, click "Start" to begin tracking your distance traveled using GPS. Drive or walk with your device to measure distance in feet, displayed in real-time. Click "Reset" to clear the distance and stop tracking. Ensure location services are enabled and allow geolocation access when prompted. For best results, use in open areas with clear GPS signals. When driving, keep phone in clear view of windshield for best signal strength. If you get random readings that seem high, give your device some time outside to calibrate with the GPS signal, and trying hitting reset, and then start again. This tool is still under developement.