Lens glint
Turns on the torch so you can sweep the room and watch for the bright pinpoint reflection a lens returns straight back at you.
What it finds
- A lens pointed roughly at you, at close range, in a dark room
What it cannot find
- A lens behind glass, fabric, or a one-way mirror
- A lens pointed somewhere else
- Anything in a bright room, where the reflection does not stand out
This check ends with you looking. The app can narrow down where to look and how strong the signal is; it cannot tell you what is there, and it never marks this check clear on its own.