I probably shouldn't have bought this thing, but curiosity got the best of me.
During my brief testing, the wireless signal detector was able sniff out a wireless router and an access point. The GPS tracker detection remains to be seen, since I don't have any of those to test it with, though it seems a bit redundant, since virtually all GPS trackers use LTE or even Bluetooth/WiFi to transmit their location, so the regular wireless signal detector mode should theoretically be more than capable of picking them up. Finally, the hidden camera detector seems more of a gimmick than anything else, since it seems (the instructions leave quite a bit to the imagination) that you're just looking for the red LEDs reflecting off a camera's lens, which I found not to work too terribly well. But it does have a blue LED that serves as a (very dim) flashlight!
