Free, open-source app Fieldwatch is a new attempt to help people discover unwanted devices such as license plate readers, cameras, and various trackers, that are increasingly cropping up in their neighborhoods, often without any warning or their local community's consent.
Fieldwatch, which is the new name for what used to be called Spectre until version 1.2.14, is available for Android and can be downloaded from the project's GitHub page as an APK, but not from Google Play.
The app's developer, who goes by the name of Off Grid Pete, says the reason for the name change was the existence of another app called Spectre.
It is made clear that this is a side project with no commercial aspirations - "This is a hobby — something I do for fun in my spare time. There is no Fieldwatch backend. There are no ads. Everything lives on the phone."
Fieldwatch works by passively listening for nearby Wi-Fi and Bluetooth LE signals and matching them against a library of device signatures.
"It's passive, it only listens, there's no dongle, no account, and no backend server. I wanted something that would work offline in the field," the developer said.
The app is not perfect - the developer is open about it, listing many limitations and potential false positives and false negatives.
The app can recognize a number of devices that are considered to be surveillance devices, as well as some that are not. Among the former are Flock Safety cameras, Axon body-worn cameras and fixed license plate readers, as well as those attached to DJI, Tello, Potensic, Holy Stone, Hubsan, Yuneec, SwellPro, Crazyflie, and Parrot drones.
It can also detect the presence of Raven, the acoustic gunshot sensor, Ray-Ban Meta glasses, as well as Osmo and LiteOn cameras.
Trackers that can be discovered by the app include Chipolo and Pebblebee, as well as those using the IETF standard for detecting unwanted location trackers. A feature flags radios that appear to be "Moving with you" as a "possible tail."
On the other hand, the app will also pick up on devices that are not surveillance gear, such as DJI power stations.
The developer is upfront about the fact that the app is not foolproof. "There is no guarantee that trackers, cameras, tags, access points, or any other device will be found, named, or reported."
Many factors can influence the app's ability to detect devices, including the fact that "radios that are off, cellular-only, asleep, randomized, quiet, or outside what this handset's OS exposes will not appear."
The matches are described as "hypotheses — not identity, not a legal finding, and not a complete RF capture."
Fieldwatch is not the first app to offer this type of functionality. Another example is ZuckOff, a free app that can detect nearby camera glasses through Bluetooth.
It was developed by Polish developer Pawel Szydlowski and it can also detect other devices, such as those made by Snapchat.
As for license plate readers, they are often installed by companies like Flock, sometimes with, but also without the explicit approval of local communities.
For example, the city council in Norman, Oklahoma rejected the cameras more than once, but they ended up in the city anyway - first through the county sheriff, and then through homeowners associations.
Meanwhile, Senators Bernie Sanders and Jeff Merkley, along with House member Alexandria Ocasio-Cortez, have sponsored the Ban Flock Act, which would prevent federal agencies from using license plate readers, or the data produced by these devices.
While efforts to at least limit the spread of this type of surveillance tech are ongoing, citizens are taking matters into their own hands by developing and using apps like Fieldwatch.
When the cameras go up without anyone asking, the least people can do is find out where they are.
