Pro Compass replicates the look and feel of classic pocket compass hardware in use since the 1800s, adding modern features and technologies. The app uses advanced OpenGL graphics (normally reserved for games) to render 3D floating compass hardware for realistic operation.Pro Compass offers nine different compass modes with needle, pointer, and rosette styles capable of displaying degrees, quads, or mils. The needle mode shows a proper "direct read" display with a North-South needle and reversed East-West convention. In all display modes, Pro Compass shows both magnetic and true direction simultaneously, with a rotating outer true ring that is automatically adjusted for local magnetic declination. Pro Compass displays location and altitude, with decimal, degree-minute-second, UTM, and MGRS position formats. An optional "Datum Pack" adds over 220 geodetic datums covering regions and countries on all continents around the world. The app also contains a built in two-axis inclinometer that drives two independent bubble levels and a bullseye level. The inclinometer has angle readout dials for each axis, making it useful for many different types of measurements including slopes, pitches, sight lines, and geological angles like dip and strike. Get Pro Compass now for just $0.99! After using Pro Compass, you'll see why it's the best and most realistic compass available on the App Store.***** IMPORTANT ACCURACY NOTE *****Pro Compass reports accuracy directly from the magnetometer hardware in your device. This accuracy is determined by the hardware, not the application itself. All apps are limited to whatever data the magnetometer provides, subject to local magnetic field conditions and interference, and all apps will have the same level of accuracy under the same conditions (Pro Compass just happens to relay this important information to the user). To improve results, operate Pro Compass away from any electronics or other sources of electro-magnetic interference, including car dashboards, aircraft cockpits, metal structures, and other devices. Under optimal conditions, accuracy can be as good as 2 degrees on newer devices, but is more typically in the 5 to 10 degree range. Under poor conditions, accuracy can drop to 20 degrees or worse on older devices. Unfortunately, this is a limitation of the device magnetometer hardware when it is dealing with magnetic interference, and is not something an app can correct.Please contact the developer via the support link if you need additional information about accuracy or operation of Pro Compass. Be aware that we are not able to respond to iTunes reviews, so please do not leave a review if you need tech support or assistance, or are confused about accuracy or operation of the app.