This app was developed for use by Amateur Radio operators with the Squaw Peak 50 mile trail run. It is designed to make it easy to track the in and out times of runners as they go through aid stations in an ultra-marathon and to allow you to transmit that data electronically across a two-way radio medium (such as an FM transmission) in order to transfer that information back to net control.
The data transfer format used is flAMP and the mode is mt63-2000L; the libraries used are open source with a special license grant from the creators of FLDIGI to make it possible to publish them for free on the app store.