TheregoDX app for iPhone and iPad

TheregoDX version 4.1 (display name: "GreatCircleDX)" displays the great circle path from a user-selected starting point location (“home”) to a selected location and displays the distance along the path in units of either statute miles or kilometers. The apps primary purpose is to aid understanding of the character and value of great circle paths, such as the relative location of home and distance places.

A great circle path as displayed on the app is the digital equivalent of stretching a string across a model globe of the earth from a "home location" to a distant location. Thus, you can instantly visualize the direction of a selected destination from either a starting location for a destination point, something you can’t do with the typical “flattened earth” Mercator projection map.

TheregoDX is similar to the app Therego, but also includes many more island locations, making it also a great way to spot many small islands around the globe. These island locations are part of the included "DXCC" list, of particular interest to amateur radio operators.

This app is not suitable for navigation.