Sight n' go for the app

My one request for the app is to have a function similar to Sight n’ Go. This is the one place where the app falls short of my Garmin GPS. I study wild animals, and as part of our research we collect fecal samples for genetic analyses. As we have to wait until the animals have moved out of the way before we can retrieve the samples, I need to be able to project a line from my position and save it, so that I know where to look for the poop.