Is Someone Tracking You? This Free GitHub Tool Can Spot Wireless Devices Following You

A free, open-source tool on GitHub is turning an ordinary smartphone into a wireless-device detection system that can identify nearby trackers, drones, cameras and other Bluetooth and Wi-Fi equipment and even alert users when a device appears to be moving with them.

Fieldwatch, created by ham radio enthusiast OffGridPete, has been designed to passively listen for nearby Wi-Fi and Bluetooth signals and classify the devices broadcasting them.

The creator says the tool can recognize signatures associated with as many as 242 types of devices.

“Fieldwatch listens for nearby Wi-Fi and Bluetooth signals and identifies the devices sending them, such as tracker tags, body cameras, drones and in-car Wi-Fi,” OffGridPete said in a social media post announcing Fieldwatch 1.1.16.

“It does this using a list of device signatures you can edit in the app,” he added. “You can get an alert when a specific device type or address shows up, and you can record a session in one place or along a drive, then compare it with later visits.”

Tool Can Highlight Devices that Appear to Follow You

One of Fieldwatch’s more notable features is its ability to identify wireless devices that appear to be traveling alongside a user. The software can record what it detects during a stationary session or while driving, allowing users to compare subsequent visits and look for recurring signals.

“Fieldwatch can also spot devices that seem to be moving with you and build reports from everything it picked up,” OffGridPete wrote.

The latest release adds a visual indicator for devices supporting DULT, or Detecting Unwanted Location Trackers. DULT is an industry specification used by Apple, Google and tracker manufacturers to communicate whether an accessory is near its owner or has become separated.

“Trackers that stand out — DULT (Detecting Unwanted Location Trackers) is the industry spec Apple, Google, and tag makers use so accessories can advertise whether they’re near their owner or separated,” the developer explained.

“Fieldwatch now shows that on the live list as a quick visual,” he said, adding that the information can be particularly useful when combined with other signals that appear to move with the user.

The software supports devices including Google Find Hub tags, newer Apple earbuds and Find My accessories, along with trackers from Chipolo and Pebblebee.

Drone Tracking and Flock Detection

Fieldwatch 1.1.16 also adds support for identifying Remote ID broadcasts from drones over Bluetooth Low Energy and Wi-Fi ASTM.

“Live status shows Undeclared, Ground, Airborne, Emergency, or RID failure,” OffGridPete said. Its reports can plot an aircraft’s advertised path as a dotted line while showing the pilot as a person icon. Detected information can also be pushed to TAK/ATAK.

The tool has also expanded its identification capabilities for Flock equipment. According to OffGridPete, the latest version provides “tighter” Flock identification, helping distinguish actual Flock poles from similar-looking LiteOn or Ring radios.

Fieldwatch was initially created as a personal project to help OffGridPete understand the wireless signals around him. He said his goal was to develop “a filtering engine so I do not have to look at everything” alongside an expandable signature library and reporting system.

Unlike services that upload wireless information to centralized databases, Fieldwatch is designed as a receive-only tool running locally on a phone.

“Same pocket tool: receive-only Wi-Fi and BLE, on the phone, no server, free and open source,” OffGridPete said.