EarthMeter
With EarthMeter you can calculate distances or areas and their circumferences with an arbitrary number of positions. EarthMeter uses algorithms that take the earth's curvature into account; therefore also far from one another measurement points also lead to correct results. Additionally, EarthMeter is able to calculate and visualize the course between two arbitrary points on earth.
All these calculations are based on a user chosen geodetic datum. As measurement units metrical and imperial linear and surface measure units are availble.
Another topic that is covered by EarthMeter is the conversion of position coordinates of one coordinate system into another one. For doing so different geodetic datums and projection methods can be chosen from the user. The user has the choice between all commonly used geodetic datums and projections.
EarthMeter supports likewise iPods, iPhones and iPads.