Compute distance and bearing using Maidenhead location. This was originally intended for use by amateur radio operators who participate in microwave communications however it can be used by any ham in order to determine a distance and bearing to another radio amateur.
This version adds a map of the source and target along with a pin annotation and an overlay identifying the six-digit grid area. If a user touches an empty location on the screen for one second a new annotation is added at that spot identifying the grid. Any user-added annotations are removed if the map view is exited and re-entered.