Field technicians are instructed to collect samples at pre-defined intervals such as "from coordinates x,y, travel straight bearing n degrees, collecting a sample every 50 metres". They currently use handheld GPS devices to accomplish this.

With turf, we could hide an app on mobile containing the point and bearing data for each traverse, record-link into the sampling app and report to the technician their "current" distance from their start/end points, as well as bearing/distance "off of" what would have been a straight line traverse.

Now that I read all of that, this might be a solution to a problem only we would ever have.