Life Signal - Offline SOS Mesh

Life Signal is a vital emergency network utility designed to function during earthquakes, floods, landslides, forest fires, or cellular blackouts without any internet or cellular network. Using Bluetooth and Wi-Fi Direct, it establishes a decentralized offline mesh network between nearby devices to route your emergency requests to search-and-rescue teams.

WHY CHOOSE LIFE SIGNAL APP?
• No Internet or Cellular Connection Required: Works fully offline without mobile data (GSM), SMS, satellite connection, or Wi-Fi.
• Multi-Hop (Mesh) Data Transmission: Your emergency messages and status jump from device to device like stepping stones, reaching distant locations and rescue teams.
• Critical Battery Preservation (Blackbox Mode): When device battery drops below 5%, the device automatically transmits your last known GPS coordinates and status to nearby nodes and optimizes broadcast for maximum energy savings.

KEY FEATURES AND EMERGENCY TOOLS:
• Offline Mesh SOS Broadcast: Distribute your health and safety status ("I am Safe", "Injured", "Trapped", or "Need Logistics") to nearby devices and rescue boards without internet.
• Acoustic Audio Beacon: High-frequency periodic siren loop designed to help search-and-rescue teams locate you using directional microphones.
• Morse Flashlight SOS: Synchronizes your camera flash to pulse the international SOS Morse code signal to stand out visually in dark ruins.
• Real-Time Earthquake Alerts: Follow recent earthquake activities globally with custom magnitude, depth, and region filters (automatically updates when internet is available).
• Cached Offline Maps: View designated assembly points, safe zones, and reported hazards on pre-cached maps even when there is no internet connection.
• Family Safety List: Monitor the last known status, coordinates, and battery level of your family circle offline via the local mesh network.
• Shake to SOS: Activate the emergency broadcast in panic situations by simply shaking the phone instead of searching for buttons.

HOW DOES OFFLINE MESH WORK?
The app connects directly peer-to-peer with other Life Signal users nearby. Each device acts as a router. Your distress signal is transmitted to a nearby phone, which automatically relays it to other devices in its range. This chain reaction carries your signal for kilometers until it reaches an internet-connected gateway or a rescue worker.

EMERGENCY GUIDE:
1. When Shaking Starts: Drop, Cover, and Hold on. Stay away from windows and elevators.
2. After the Shaking Stops: Open the Life Signal app immediately and update your emergency status.
3. If Trapped: Activate the "Audio Beacon" (Acoustic SOS) and keep the phone in Morse strobe mode. Avoid checking the phone constantly to preserve battery.

PRE-DISASTER CHECKLIST:
1. Cache Offline Maps: Go to settings and download your local city map.
2. Establish Family Circle: Connect with your family members via Bluetooth.
3. Grant Permissions: Approve Location, Bluetooth, and Camera permissions in advance.

PRIVACY & SECURITY:
Life Signal is built on decentralized architecture. No central servers are used; your coordinates, health profiles, and blood types remain encrypted on your device and are only shared via the offline local mesh network during an active emergency.