This learning and free compass app explains everything you need to know about compasses (magnetic and gyro types). Variation, deviation and gyro error are clearly explained in the theoretical section and practically applied in the calculator section. You can calculate heading relations in two directions: from compass to map and from map to compass. This can be done for magnetic compass and for gyro compass. The calculator can be used both as a learning process and in real life situations. The strong point about this app is the fact that the calculation result is not simply showing the output values, but also the calculation details step by step, so that you can learn and understand what happens. Also a plot is shown explaining the difference between true north, magnetic north and compass north. Make sure you understand this well. Further you can find a compass check calculating the deviation based on a true bearing and the type of steering compass used. Check the detailed calculation steps so that you understand how it works. The theoretical section is a real reference and very instructive, containing 9 easily readable sections. In section 6 you will find the most used formula's as a reference. As a bonus we have added 3 extra tools. A tool for calculating the magnetic variation, and a tool for calculating the azimuth of the sun and the moon, based on time, date and position. Position is using built in location data. Make sure location is activated using high accuracy. The tool for the magnetic variation is really practical in use. it calculates with high precision the magnetic variation for any location and time. It is based on the World Magnetic Model for the period 2015-2020. The tools for sun and moon azimuth may be used to obtain the compass errors in case there are no leading or range lights available. We wish you a great learning experience with this compass calculator app.