Oksigenia SOS 🏔️ v4.1.1 "Smart Beacon"

The Ultimate Outdoor Guardian | FOSS | Privacy-First | Autonomous

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🦅 Why Oksigenia SOS?

When you are alone in the mountains, technology is your last line of defense. Most safety apps rely on internet connection, proprietary servers, or paid subscriptions. Oksigenia SOS is different.

It is an autonomous bio-telemetry system designed to detect life-threatening situations (severe falls or prolonged unconsciousness) and automatically trigger a rescue protocol using pure SMS.

• No Servers: Your data never leaves your phone.
• No Internet: Works via GSM/SMS (2G/3G/4G/5G).
• No Accounts: Install, configure, and you are protected.

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📸 Visual Tour

The interface is designed for high-stress situations. High contrast, large touch targets for gloved hands, and clear status indicators.

Flight Deck	Fall Detected	Inactivity Alert	Configuration
Real-time telemetry & status	30s countdown before SMS	Triggered by lack of motion	Local contacts & settings

Test Mode	Alert Sent	SMS Payload	Localization
Safe testing environment	Confirmation screen	Direct GPS coordinates	8 Native languages

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📍 What's New in v4.1.1: Smart Beacon (RB hot-fix of v4.1.0)

v4.1.1 carries the v4.1.0 feature set unchanged. The only difference is a Reproducible Build hot-fix: the release workflow now strips the build-id embedded by the linker into libdartjni.so (transitive jni dep), so the APK is bit-for-bit reproducible and IzzyOnDroid can certify it (Issue #6).

The user-visible features below all originate from v4.1.0:

📡 Smart Beacon — Post-SOS Position Updates

After an SOS is sent, Sylvia automatically watches the victim's GPS position. If the user moves more than 300 m from the last known reference, an SMS update is sent with the new coordinates. The flagship use case: a hiker who, after the alarm, gets disoriented and walks the wrong direction — rescuers arriving 2–4 hours later need fresh coordinates, not the original incident point.

• Throttled to one SMS every 5 minutes
• Capped at 20 updates over a 4-hour window
• Battery cost while stationary: zero (no SMS sent until movement is detected)
• Stops automatically when the user taps "Restart system"

Smart Beacon is automatic (post-SOS only) and complementary to the existing voluntary Live Tracking, which sends periodic check-ins on demand.

🐴 Equitation Profile

Seventh activity profile for horse riding. Impact detection is disabled (horse cadence interferes with the human-walk detector). Inactivity Monitor + manual SOS protect during the ride. Same conservative approach as Paragliding and Kayak.

🌍 Three new languages

• 🇵🇱 Polish — Tatra/Beskid hiking, FOSS-friendly community
• 🇷🇺 Russian — Caucasus, Altai, Urals
• 🇳🇴 Norwegian Bokmål — friluftsliv

Now 11 languages total (en, es, fr, de, pt, it, nl, sv, pl, ru, nb).

See the v4.1.1 GitHub Release for the full technical breakdown.

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🛡️ v4.0.0: Smart Sentinel Complete

Closes the multi-sport story started in v3.9.7. Three additions on top of the existing Smart Sentinel v4 algorithm and activity profiles.

⚡ Catastrophic Impact Path

A second G-force threshold per profile fires the alarm immediately, skipping the 60-second yellow observation window. The 30-second pre-alert on the alarm screen is still the user's chance to cancel.

Profile	Yellow (observation)	Orange (direct alarm)
🥾 Trekking	6G	10G
🚵 Trail / MTB	8G	13G
🧗 Mountaineering	6G	10G
🪂 Paragliding	impact off	impact off
🛶 Kayak	impact off	impact off
👷 Professional	6G	10G

📍 GPS Interval per Profile

Each profile declares its own GPS sampling rate. Slow-motion sports save battery; fast-motion sports get the resolution they need. Applied mid-session when the user changes the active profile.

Profile	Interval	Distance filter
🥾 Trekking / 🧗 Mountaineering	30 s	30 m
🚵 Trail / MTB / 👷 Professional	5 s	10 m
🪂 Paragliding	2 s	5 m
🛶 Kayak	15 s	20 m

🏠 Home Screen Widgets

Two AppWidgets, native Kotlin, zero new dependencies, zero new permissions.

• 🆘 Panic widget (1×1): circular SOS button. Tap fires the alarm flow directly with the 30-second pre-alert as safety. Works even if monitoring is currently off — wakes the foreground service if needed.
• 📊 Status widget (2×2): active profile (with emoji), Sentinel state (green/yellow/orange/red dot), active modes (fall detection, inactivity monitor with configured time, live tracking), battery level. Updates once per minute.

🛠️ Resolves Issue #3

Issue #3 reported false positives during paragliding. v4.0.0 ships a Paragliding profile with impact detection disabled entirely; in flight only Inactivity Monitor + manual SOS protect.

See the v4.0.0 GitHub Release for the full technical breakdown.

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🎯 v3.9.7: Smart Sentinel v4 & Activity Profiles

🧠 Smart Sentinel v4 — Cadence-CV Detector

The fall-detection algorithm has been rewritten from scratch using field telemetry collected on Pixel 7a and Pixel 8 phones in pocket while walking real terrain.

• Horizontal-plane cadence (√(effX² + effY²)) using userAccelerometerEventStream — gravity is removed by the platform; vertical bobbing is filtered out.
• Z-bias EMA filter (α = 0.998) — corrects a Pixel 8 firmware quirk where the Z axis sticks at ~197 m/s² for several seconds.
• Runtime Hz measurement — Pixel 7a delivers 58.8 Hz, Pixel 8 delivers 49.8 Hz (not the 50 Hz the old code assumed). Frequency now self-calibrates per device.
• CV cap raised to 1.30 (was 0.85) — the wearable literature's "CV ≈ 0.4" is wrong for a phone in a pocket. Median measured CV in real walking is 1.1.
• Crossing threshold raised to 1.12 m/s² (was 1.06) — sits above hand-carried noise.
• File logger at app_flutter/sentinel.log for post-incident analysis.

🏃 Activity Profiles

Six presets tune Smart Sentinel sensitivity to match the sport. Pick from the home screen chip or Settings.

Profile	Impact threshold	Cadence band
🥾 Trekking (default)	Standard	Walking
🚵 Trail / MTB	Higher	Wider
🧗 Mountaineering	Standard	Slow
🪂 Paragliding	Disabled	—
🛶 Kayak	Disabled	—
👷 Professional	Sensitive	Standard

Profiles apply mid-session — no restart needed.

🛠️ Pixel 7 / Android 14 Stability

• FGS type fix: Removed foregroundServiceType=location from the manifest (kept dataSync|mediaPlayback). The old declaration broke WatchdogReceiver background restarts on Android 14+.
• setMonitoring race: _loadSettings now awaits toggleInactivityMonitor and skips the redundant setMonitoring event that caused intermittent cold-start failures.

🔒 Privacy — Telephony Stack Replaced

The unmaintained telephony ^0.2.0 package was injecting a transitive READ_PHONE_STATE implied permission. Replaced with the active fork another_telephony ^0.4.1. APK verified with aapt dump permissions — zero phone-state permissions in the release build.

See the v3.9.7 GitHub Release for the full technical breakdown.

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🥾 v3.9.6: The Trekking Update

📡 Live Tracking

Stay connected with your emergency contact even when nothing goes wrong.

• Periodic SMS check-ins: Send your GPS position automatically every 30, 60, or 120 minutes.
• Countdown timer: "Next check-in in: MM:SS" visible in the status pill and telemetry panel.
• Pause / Resume: Temporarily suspend check-ins (e.g. during a rest) without deactivating monitoring.
• "I'm OK" button: Manual instant check-in that resets the countdown.
• Auto-Pause on SOS: Check-ins suspend automatically when a fall alarm fires, and resume if the alarm is cancelled.

⏰ Doze Mode — Verified

After 1 hour of real-world sleep on a locked Pixel 8 running GrapheneOS, the alarm broke through the lock screen correctly. AlarmManager.alarmClock is used for scheduling instead of Timer.periodic (which freezes in deep Doze). The alarm fires, displays the full-screen countdown, and allows cancellation without unlocking.

🧭 Onboarding Overhaul

• GrapheneOS SMS guide: Step-by-step instructions for the Android 13+ "Allow restricted settings" flow. The app walks you through the required sequence (denied notice → ⋮ menu → PIN → permissions) that sideloaded apps must follow to gain SMS access.
• Motion Sensor detection: Automatically detects if the device's sensor access is disabled (GrapheneOS "Sensors" toggle) and prompts you to enable it before monitoring begins.
• "Why these permissions?" panel: Each permission has an explanation. Swipe up the bottom sheet to understand exactly what each permission is used for — and what happens if you deny it.
• Language selector: Change the app language directly from the onboarding screen, without navigating to settings.

🔒 Privacy Fix

Removed implicit READ_PHONE_STATE permission that was being injected by a transitive dependency. The APK no longer requests or implies this permission.

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🚀 The v3.9.5 Saga: The Immortal Update

This version is not just an update; it is a complete re-engineering of the app's lifecycle and its survival under real field conditions.

🏗️ Phase 1: Modernization

We have migrated the entire codebase to Flutter 3.38.

• Zero Technical Debt: All deprecated libraries have been replaced.
• Linter Compliance: The code is clean, strict, and optimized for the latest Android runtimes.

💔 Phase 2: The "Great Decoupling"

Previously, the logic lived inside the screen. Now, they are divorced.

• Headless Architecture: The UI is now just a "Remote Control".
• Service Independence: If you close the UI, the Service DOES NOT DIE. It continues monitoring acceleration and inactivity in a separate Isolate.
• Smart Reconnection: When you open the app, it asks: "Is a service already running?" If yes, it connects to the live stream. If no, it initializes the system.

🧛 Phase 3: Deep Sleep Immunity

We fought against Android's Doze Mode and won.

• CPU Wakelock: The background service holds a PARTIAL_WAKE_LOCK (native Android) to keep the CPU alive for sensor processing even in deep sleep.
• Battery Gate: Monitoring cannot be activated unless the app is exempt from battery optimization. This is not a warning — it is a hard block. A single tap opens the system setting to fix it.
• Zombie Recovery: If an alarm triggers while the phone is locked, the system recovers instantly on unlock with the correct remaining countdown.

🔔 Phase 4: The Alarm Breaks Through

The alarm is now a true emergency signal, not just a notification.

• Lock Screen Override: When a fall or inactivity alarm triggers, the app appears directly on top of the lock screen using Android's fullScreenIntent. The user can cancel the alarm without unlocking the phone — critical when wearing gloves or in cold conditions.
• No More Frozen Screenshot: The lock screen no longer shows a static, non-interactive snapshot of the app UI. Normal lock behavior is fully restored when no alarm is active.
• Screen-On Guarantee: The alarm forces the screen on and keeps it lit for the full 30-second countdown window.

🧠 Phase 5: Smart Sentinel

Intelligent fall detection that eliminates false positives from physical activity.

• Impact → Observation: A >3.5G impact does not trigger the alarm immediately. It opens a 60-second silent observation window.
• Rhythmic Movement Detection: Every 2 seconds, the service analyzes the last 60 sensor samples. If it detects rhythmic acceleration crossings (walking, running, cycling), it classifies the event as a false positive and resets silently.
• True Fall Confirmation: Only sustained absence of rhythmic movement for 60 seconds triggers the alarm. Falls while hiking, scrambling, or riding do not cause false alerts.
• Re-arm After Cancel: The Sentinel re-arms correctly after the user cancels an alarm. The sensor buffer is cleared on reset to prevent stale data from contaminating the next analysis cycle.

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🧠 Core Features

Feature	Technical Detail
📊 Live Telemetry	The footer displays real-time sensor data. G-Force Meter visualizes acceleration vector sum. Battery monitoring triggers an emergency "Dying Gasp" SMS at <5%.
📐 Vector Physics	3D Vector Magnitude Calculation ($\sqrt{x^2+y^2+z^2}$). Smart Sentinel filters walking, running, and cycling as false positives before triggering.
🛡️ Permission Semaphores	Instantly shows if you are safe. Green: Systems Go. Red: Critical permission missing. Tapping guides you to the specific Android setting.
🌑 Dictatorship of Dark Mode	Enforced pure dark theme (OLED friendly). Preserves night vision and maximizes battery life.
🧟 Inactivity Monitor	Runs fully in the background. Tracks micro-movements even with the screen off. Configurable timeout (hours).
🪫 Dying Gasp	At battery <5%, automatically sends an SMS with last known GPS coordinates before power death.

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⚠️ Critical Configuration

These settings are required for Oksigenia SOS to function reliably in the field. The app will not allow monitoring to start until they are configured.

🔋 1. Battery Optimization — Unrestricted (Mandatory)

• Why? Android kills background processes to save power. Without this, the Sentinel dies after a few hours of inactivity.
• How: Long press App Icon → App Info → Battery → Select "Unrestricted" (or "Don't optimize").
• The monitoring toggle will not activate until this is set. Tapping the battery icon opens the correct setting directly.

📺 2. Full-Screen Notifications — Allow (Mandatory on Android 14+)

• Why? Required for the alarm to appear on top of the lock screen without manual unlock.
• How: Go to Settings → Apps → Oksigenia SOS → Full-screen notifications → Enable.
• Without this, the alarm audio still plays but the screen does not wake automatically.

🛡️ 3. Allow "Restricted Settings" (Android 13+)

• Why? Android blocks apps from sending SMS automatically. You must authorize Oksigenia manually.
• How: Go to Settings → Apps → Oksigenia SOS → Tap three dots (⋮) → "Allow restricted settings".

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🌍 Global Availability

Oksigenia SOS is fully localized in 11 languages:

• 🇬🇧 English
• 🇪🇸 Español
• 🇮🇹 Italiano
• 🇫🇷 Français
• 🇩🇪 Deutsch
• 🇵🇹 Português
• 🇳🇱 Nederlands
• 🇸🇪 Svenska
• 🇵🇱 Polski
• 🇷🇺 Русский
• 🇳🇴 Norsk Bokmål

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🛠️ Build & Contribute

We believe safety tools should be open and auditable.

📦 Download

Get the latest signed APKs from the Releases Section.

💻 Build from Source

Requirements: Flutter 3.38.7 (exact version — required for Reproducible Builds)

git clone https://github.com/OksigeniaSL/oksigenia-sos.git
cd oksigenia-sos
flutter pub get
# Note: You need your own key.properties for release builds
flutter build apk --release --split-per-abi

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💚 Support the Project

Oksigenia SOS is — and will remain — free, open-source, and free of commercial commitments. If the app has been useful to you or gives you peace of mind when you head outdoors, you can support its development:

Donations help cover development costs (test hardware, domains, tools) and the time spent maintaining the app, translations, and field validation across all the activity profiles.