A viewfinder for the light your eyes can't see — near-infrared leakage, low-light detail, and thermal-style false color.
Your phone's sensor is naturally sensitive to near-infrared light, but a physical IR-cut filter blocks most of it before it reaches software. Scope can't remove that filter — no app can — but it can amplify and recolor whatever leaks through, and catch fast IR pulses like a TV remote.