Digital Compass

The Untangled Labs Digital Compass uses your device's built-in magnetometer and orientation sensors to display a real-time true-north heading. Features include automatic magnetic declination correction using the NOAA World Magnetic Model, iOS and Android compatibility, bearing lock mode, figure-8 calibration instructions, 4-zone audio beeps for hands-free alignment, and a manual fine-tune slider. Works in any browser that supports the DeviceOrientation API with sensor permissions granted. Free GIS tool, no account required.