These will only detect metals within 2–4 inches of your phone. They are not "satellite scanners."
Avoid this app. Use a legitimate magnetic sensor app for fun, but understand its severe limitations. For serious metal detecting, buy a real detector. Satellite Nasa Metal Scan Apk App Download For Android
: Provides access to NASA+ streaming, over 21,000 images, the latest mission news, and a tracker for the International Space Station (ISS). These will only detect metals within 2–4 inches
If it sounds too good to be true (NASA satellite metal detection on a free app), it is a trap. the latest mission news
Legitimate apps use your phone's (a built-in magnetic field sensor) to detect nearby metallic objects.