RFmarcus@ctOS-2.0:~$ ./rf_sentinel --passive
RF_SENTINEL
A free, open-source Android app that listens to Bluetooth LE advertisements and WiFi beacons around you and flags police and surveillance equipment: body cameras, Flock and other plate-reader cameras, patrol-vehicle gear, trackers following you, Remote ID drones and camera glasses. It also watches the cell network for fake-tower (IMSI catcher) signs.
RX ONLYNo root · no Termux · no account · no analytics · GPL-3.0 · Android 8.0+
Signed APK from GitHub Releases. Not on Google Play. Install guide · Q&A
What it detects
| Category | Examples | How |
|---|---|---|
| Body cameras | Axon (TASER), Motorola / WatchGuard, Digital Ally, Zepcam, Vievu, Utility, Getac, in-car video | BWCDEVICE payload tag, company ID 0x034D, service UUIDs 0xFC81 / 0xFE6B / 0xFE6C, IEEE vendor prefixes |
| License-plate readers (ALPR) | Flock Safety, Genetec, Perceptics, Quercus, Tattile | Flock- SSIDs, Penguin- / FS- / FS Ext Battery BLE names, company ID 0x09C8, plus OpenStreetMap / DeFlock camera locations |
| Speed & red-light cameras | Fixed cameras mapped in OpenStreetMap | Offline map layer, warned about ~30 s ahead with the mapped limit |
| Audio sensors | Flock Raven gunshot detectors | 128-bit service UUIDs with short IDs 0x3100-0x3500 |
| Patrol vehicles | Two or more kinds of police-type gear moving together | RSSI correlation (Pearson r ≥ 0.6 over ≥ 8 s) across body cam, radio, in-car router, printer, rugged laptop roles |
| Public-safety gear | P25 / TETRA radio makers, police radar makers, vehicle upfit, Zebra e-ticket printers | Company IDs, UUIDs, IEEE prefixes, Zebra factory-serial names |
| Trackers | AirTag & Find My, Google Find Hub, Samsung SmartTag, Tile | Separated-from-owner frames, then follow detection (default 10 min and 800 m with you) |
| Drones | Any ASTM F3411 / FAA Remote ID broadcaster (DJI, Skydio, Autel, Parrot...) | Decoded Remote ID over BLE and WiFi: serial, position, altitude, speed, heading, operator location |
| Camera glasses | Ray-Ban Meta, Snap Spectacles, Vuzix, HeyCyan-based glasses | Luxottica 0x0D53, Snap 0x03C2, Vuzix 0x060C, Meta UUIDs |
| Fake cell towers | IMSI catchers / cell-site simulators | Test MCCs, sudden 4G→2G, cloned or reserved cell IDs, unexpected networks (no root) |
Every match shows its evidence, its source and a confidence tier: weak (< 50), probable (50-79) or strong (80+). Full rules: how detection works and the signature reference.
What happens to every packet
Illustrative trace: actual scores depend on what each device advertises. The app logs the evidence the same way on each device's detail screen.
Features
Live list & radar
Every device heard in the last 3 minutes with vendor, type, radio, RSSI, rough distance and NEW / ★ / FOLLOWING badges. Flagged devices sort first. Filter chips with live counts.
Alerts
Sound, vibration pattern per tier (1 / 2 / 3 pulses), spoken announcements through the phone's TTS, discreet mode, floating threat bubble over Waze or Google Maps.
Map & traces
OpenStreetMap with your GPS trace, devices placed where their signal peaked, history heatmap and timeline, offline known-camera layer.
Android Auto
Template app with threat headline, device lists, live OSM map with cameras and drones, turn-by-turn navigation, alerts through the car speakers. Details
Auto start in the car
Starts when the phone connects to your car's Bluetooth or Android Auto, stops when you leave.
ESP32 boards
OUI-Spy over USB OTG or Bluetooth, GhostESP over USB. The board's detections merge into the app. Details
Device details
Evidence, identity, decoded protocol data, signal graph, Locate mode (beeps faster as you get closer), history and the raw advertisement.
Export
CSV, JSON, KML, GPX, GeoJSON. Everything stays on the phone until you export or share it.
13 themes
Including DedSec (Watch Dogs 2) and fsociety (Mr. Robot) fan themes with animated terminal headers, Night Drive red HUD, Night Vision, Amber CRT.
Screenshots
Screenshots use made-up demo devices run through the real detection pipeline.
Compared with other options
| RF Sentinel | SØPHIA (CIVOPS) | Phone's built-in tracker alerts | |
|---|---|---|---|
| Price | Free | Paid | Free |
| Open source | GPL-3.0 | No | No |
| Install | Regular APK | Termux + Termux:API | Built in |
| Bluetooth LE signatures | Yes | See vendor | Trackers only |
| Police / ALPR / body cam rules | Yes, sourced | See vendor | No |
| Remote ID drone decode | Yes | See vendor | No |
| Fake cell tower signs | Yes | See vendor | Android 15+ only (network notifications) |
| Android Auto | Yes | No | No |
More in RF Sentinel vs SØPHIA. RF Sentinel is an independent project, not affiliated with SØPHIA or DetecX.
Guides
Detect police with Android
Body cams, radios, patrol-vehicle kits, e-ticket printers.
Flock & ALPR cameras
Radio signatures plus the OpenStreetMap / DeFlock camera map.
Stingray / IMSI catcher
What a non-rooted phone can and can't see.
AirTag & tracker detection
Find My, Find Hub, SmartTag and Tile on Android.
Remote ID drone detector
Drone and operator position from the broadcast.
Smart glasses detector
Ray-Ban Meta, Spectacles, Vuzix nearby.
Privacy
- Receive-only. The app never transmits, jams, spoofs or connects to the devices it detects.
- No accounts, no cloud, no analytics. Detections live in a local database excluded from cloud backup.
- Network use: OpenStreetMap map tiles and camera data (Overpass API, DeFlock CDN), and in Android Auto, Nominatim search and OSRM routing, only when used. Those servers see your IP and the area or route, never your scans.
- Data leaves the phone only when you export or share it.