Specter: Open-source NFC reader bug sweep for Flipper Zero

Specter is a Flipper Zero app that finds powered NFC readers by listening for the radio field they give off. The readers it hunts work at 13.56 MHz. The Flipper’s own chip does the sensing The onboard ST25R3916 carries a hardware external-field detector, the same circuit that lets the device emulate a card and register when a reader starts talking to it.