OffGridPete writes that Fieldwatch is a passive, receive-only Android app that listens for nearby Wi-Fi access points and Bluetooth LE advertisements to help users identify radio sources around them. Built as a personal hobby tool, it runs entirely offline with no account, no backend server, and no dongle. The app was originally named Spectre but was renamed to avoid confusion with another existing app, and it is distributed as a sideload APK under the MIT License.
- Includes an extensible signature library for identifying radio sources
- Features GPS co-travel detection ("possible tail") and a Debrief report
- Privacy mode can mask Remote IDs on-screen while full coordinates are retained in logs
- Not capable of capturing Wi-Fi probe frames, Bluetooth Classic, cellular, or direction-finding data
- Includes an extensible signature library for identifying radio sources
- Features GPS co-travel detection ("possible tail") and a Debrief report
- Privacy mode can mask Remote IDs on-screen while full coordinates are retained in logs
- Not capable of capturing Wi-Fi probe frames, Bluetooth Classic, cellular, or direction-finding data
