USELESS SKIP IT DONT WASTE YOUR TIME.
Response from developer
Sorry to hear it didn't work for you. The app uses the phone's magnetometer to detect the metal screws and nails that hold drywall to the studs, so it needs a calibration away from any metal, the phone flat against the wall, a slow pass and a sensitivity setting that suits your wall; it is weaker on lath-and-plaster walls. Subscriptions are managed by Apple: Settings → your name → Subscriptions lets you cancel in two taps, and refund requests go through reportaproblem.apple.com. If you tell us what kind of wall you scanned, we're happy to help.
Useless
The app doesn’t work
Trash
Don’t waste your time!
Response from developer
We are sorry the app did not work out for you. It detects the metal fasteners inside a stud rather than the timber, so results depend a lot on technique: calibrate away from metal, keep the phone flat, and move slowly across the wall. Lath-and-plaster walls are the hardest case, and there the sensitivity setting makes the biggest difference.
