I wrote a post this weekend about the mobile media scavenger hunt platform and app, GooseChase. My wife and I have used GooseChase for three different workshops this summer, and it has been great! Highly recommend it. http://www.speedofcreativity.org/2017/08/05/mobile-media-scavenger-hunts-with-goosechase/
@dogtrax wow sorry for the late reply - haven't been on Mastodon lately! Yes by all means you should give GooseChase a try. Should work for distributed / geographically separated groups well.
Generalistic and moderated instance.