Flock-You

Open-Source Counter-Surveillance for Android

"Watch the Watchers" - Know when surveillance equipment is nearby so you can protect your privacy, document police presence, or simply understand the surveillance landscape around you.

Flock-You is a privacy-first surveillance detection application that empowers individuals to identify surveillance devices, trackers, IMSI catchers, and other monitoring equipment in their environment. All processing happens entirely on-device with zero cloud connectivity.

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Table of Contents

• Features
• Detection Capabilities
• Privacy Architecture
• Flipper Zero Integration
• Installation
• Build Variants
• OEM Integration
• Contributing
• Security Considerations
• Resources
• License

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Features

Multi-Spectrum Detection

• 7 Detection Protocols: BLE, WiFi, Cellular, GNSS, Ultrasonic, RF, and Satellite
• 75+ Device Signatures: From AirTags to IMSI catchers to Flock Safety cameras
• Real-Time Alerts: Configurable notifications with threat severity levels
• Stalking Detection: Behavioral analysis to identify trackers following you

Privacy-First Design

• 100% On-Device Processing: No cloud, no telemetry, no analytics
• Encrypted Database: SQLCipher AES-256-GCM encryption
• Ephemeral Mode: Optional RAM-only storage that leaves no trace
• Configurable Retention: Control how long detection history is kept

Security Features

• Duress PIN: Secondary PIN that triggers secure wipe
• Nuke Manager: Multi-pass secure data destruction
• Auto-Purge: Wipe data on screen lock or failed auth attempts
• Dead Man's Switch: Time-based automatic data destruction

Hardware Integration

• Flipper Zero: Extended scanning via Flock Bridge FAP
• External Radios: ESP32, CC1101, nRF24L01+ support
• Multi-Board Support: GINTBN and similar expansion modules

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Detection Capabilities

Bluetooth LE Trackers

Anti-Stalking Features:

• Detects trackers appearing at 3+ distinct locations
• "Possession signal" when tracker has strong, consistent RSSI (-40 to -55 dBm)
• Duration-based scoring for extended tracking periods
• Guidance for physical search and evidence preservation

WiFi Surveillance

Advanced Detection:

• Following network detection (vehicle-mounted APs tracking movement)
• Deauthentication flood monitoring
• Hidden network with strong signal alerts
• Channel congestion analysis

Cellular (IMSI Catcher Detection)

Cellular Monitoring:

• Trusted cell tower learning
• LAC/TAC anomaly detection
• MCC/MNC validation
• Cross-reference with location and movement

GNSS/GPS Security

Satellite Analysis:

• Multi-constellation support (GPS, GLONASS, Galileo, BeiDou)
• Carrier-to-noise ratio monitoring
• Pseudorange consistency checks
• Position solution validation

Ultrasonic Tracking

Audio Analysis:

• FFT-based frequency detection
• Pattern matching against known beacon signatures
• Amplitude and duration filtering
• Consent-based activation (requires user acknowledgment)

Satellite/NTN Monitoring

Satellite Heuristics:

• Unexpected satellite connection when terrestrial available
• Timing inconsistent with claimed orbital position
• Rapid/suspicious handoff patterns
• Frequency mismatch for claimed satellite type

RF Analysis

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Privacy Architecture

┌─────────────────────────────────────────────────────────────┐
│                      YOUR DEVICE                             │
│                                                              │
│  ┌──────────┐  ┌──────────┐  ┌──────────┐  ┌──────────┐    │
│  │   BLE    │  │   WiFi   │  │ Cellular │  │   GNSS   │    │
│  │ Scanner  │  │ Scanner  │  │ Monitor  │  │ Monitor  │    │
│  └────┬─────┘  └────┬─────┘  └────┬─────┘  └────┬─────┘    │
│       │             │             │             │           │
│       └─────────────┴──────┬──────┴─────────────┘           │
│                            │                                 │
│                   ┌────────▼────────┐                       │
│                   │   Detection     │                       │
│                   │   Processing    │                       │
│                   └────────┬────────┘                       │
│                            │                                 │
│                   ┌────────▼────────┐                       │
│                   │  Threat Scoring │                       │
│                   │     Engine      │                       │
│                   └────────┬────────┘                       │
│                            │                                 │
│                   ┌────────▼────────┐                       │
│                   │   SQLCipher     │                       │
│                   │  Encrypted DB   │                       │
│                   └────────┬────────┘                       │
│                            │                                 │
│                   ┌────────▼────────┐                       │
│                   │    User UI      │                       │
│                   └─────────────────┘                       │
└─────────────────────────────────────────────────────────────┘
                            ║
                     ══════╬══════  NO CONNECTION
                            ║
              ┌─────────────▼─────────────┐
              │       Cloud Services       │  ← BLOCKED
              └───────────────────────────┘

Privacy Guarantees

Data Retention Options

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Flipper Zero Integration

Flock-You includes Flock Bridge, a Flipper Zero FAP (Flipper Application Package) that extends detection capabilities with dedicated hardware.

Flock Bridge Features

Passive Scanners:

• Sub-GHz (315/433/868/915 MHz) - RF signal detection
• BLE - Tracker and device scanning
• WiFi (via ESP32) - Network discovery and WIPS
• IR - Infrared signal capture
• NFC - Card and tag detection

Active Probes (Authorized Testing Only):

• Sub-GHz replay
• WiFi probe requests
• TPMS wake-up
• Traffic light preemption testing
• Wireless keyboard injection

WIPS Engine:

• Evil twin detection
• Deauthentication flood monitoring
• Karma attack identification
• Weak encryption alerts

Hardware Requirements

Connection

Flipper GPIO Header → ESP32 UART
Pin 13 (TX) ──────── RX (GPIO 16)
Pin 14 (RX) ──────── TX (GPIO 17)
GND ────────────────── GND
3.3V ───────────────── 3.3V

See Flock Bridge README for complete documentation.

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Installation

Requirements

• Android 8.0 (API 26) or higher
• Location permission (required for BLE/WiFi scanning)
• Microphone permission (optional, for ultrasonic detection)

From Release

1. Download the latest APK from Releases
2. Enable "Install from unknown sources" if needed
3. Install the APK
4. Grant requested permissions

From Source

# Clone the repository
git clone https://github.com/FlockYou/Flock-You-Android.git
cd Flock-You-Android

# Build debug APK
./gradlew assembleSideloadDebug

# Install to connected device
./gradlew installSideloadDebug

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Build Variants

Flock-You supports three build flavors for different deployment scenarios:

Building Variants

# Sideload (standard)
./gradlew assembleSideloadRelease

# System (priv-app)
./gradlew assembleSystemRelease

# OEM (platform-signed)
./gradlew assembleOemRelease

Permission Differences

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OEM Integration

Flock-You is designed for OEM white-labeling and custom ROM integration.

Quick Integration (GrapheneOS/CalyxOS/LineageOS)

# Automated integration
./system/integrate-grapheneos.sh ~/grapheneos

# Or with pre-signed APK
./system/integrate-grapheneos.sh ~/grapheneos presigned

Manual Integration

1. Copy integration files:

mkdir -p ~/grapheneos/vendor/flockyou
cp system/Android.bp ~/grapheneos/vendor/flockyou/
cp system/privapp-permissions-flockyou.xml ~/grapheneos/vendor/flockyou/

2. Add to device.mk:

$(call inherit-product, vendor/flockyou/flockyou.mk)

3. Build your ROM:

source build/envsetup.sh
lunch <target>
m

Customization Points

See OEM_INTEGRATION.md for complete documentation including security considerations.

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Contributing

We welcome contributions! Please see CONTRIBUTING.md for guidelines.

Development Setup

1. Android Studio Hedgehog (2023.1.1) or newer
2. JDK 17
3. Android SDK 34

Running Tests

# Unit tests
./gradlew testDebugUnitTest

# Instrumentation tests
./gradlew connectedAndroidTest

# Lint
./gradlew lint

Commit Format

type(scope): description

feat(scan): add support for new device type
fix(ble): correct AirTag detection false positives
docs: update detection documentation

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Security Considerations

The Surveillance Paradox

To detect if you're being surveilled, this app must collect data about your environment.

What's Stored Locally:

• Detection history with timestamps and locations
• Trusted cell tower database
• WiFi network profiles
• BLE device signatures

Forensic Risk: If your device is seized, this data reveals your location history and movement patterns. Consider:

• Using minimum retention period (1 day)
• Enabling ephemeral mode for sensitive situations
• Clearing data before high-risk scenarios
• Using duress PIN if compelled to unlock

Trust Model

Verifying Builds

# Check APK signature
apksigner verify --print-certs app-release.apk

# Verify GitHub attestation
gh attestation verify app-release.apk --owner FlockYou

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Resources

Support Organizations

External Databases

Documentation

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Threat Scoring

Flock-You uses an enterprise-grade threat scoring formula:

threat_score = base_likelihood × impact_factor × confidence

Confidence Adjustments:

• +0.3 Cross-protocol correlation
• +0.2 Multiple indicators
• +0.2 Persistence over time
• -0.3 Single weak indicator
• -0.5 Known false positive pattern

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Legal Disclaimer

This software is intended for authorized security research, personal privacy protection, and educational purposes.

• Only use detection features passively
• Active probing features (Flipper Zero) require authorization
• Radio transmission may be regulated in your jurisdiction
• The authors are not responsible for misuse

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License

MIT License - See LICENSE for details.

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Acknowledgments

• Flipper Zero - Hardware platform
• SQLCipher - Database encryption
• EFF - Privacy advocacy and resources
• The open-source security research community

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Flock-You: Watch the Watchers
Privacy-first surveillance detection for Android

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