Was hunting a cellar used for the Underground Railroad . Room was 8x8, 5 1/2 feet high with dirt floor. Must have sucked but was told they never stayed long, had to keep moving. Whole hunt was videotaped for a later documentary . Found a small pocket knife, a flat button, and a weird piece of metal. After, we were talking and someone thought there was an app to iD things from pictures kinda like facial recognition. Any one know anything about that ???