Magnet sweep
Reads the phone's compass sensor and reports where the magnetic field jumps, because most stick-on vehicle trackers are held on by strong magnets.
What it finds
- A strong magnet close to the phone, such as a magnetic tracker case under a car
- The place a field is strongest, so you know where to look
What it cannot find
- A tracker that is not magnetically mounted, such as one wired into the car
- A tracker plugged into the car's diagnostic port
- Anything further away than roughly a hand's width from the phone
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.