We paid way too much money for a wildlife tour because we had learned soooo much from this app. Its the very best $5 we spent on our vacation. It doesnt matter if you are there for 1 day or a whole weeklike us - this app will help you see and understand what really makes this park special. We had horrible cell service and that didnt matter because it ran off GPS. I cant say enough about how much this simple app enhanced our experience in Yellowstone!!