CardioVox: Voice Heart Zones

Train smarter, stay focused, and keep your phone in your pocket. CardioVox gives you instant, hands-free voice announcements whenever your heart rate transitions between workout zones. Powered by ultra-fast offline neural AI speech synthesis (Piper TTS) as well as your phone's built-in system speech engine, CardioVox delivers natural, real-time voice feedback without requiring an active internet connection or paid subscription.

Whether you are cycling, running intervals, rowing, or training for endurance, CardioVox ensures you hit your target training zones without glancing at your watch or phone screen.

🌟 Key Features
Hands-Free Audio Zone Alerts: Get voice announcements the moment your heart rate enters and stays in a new training zone. Configurable dwell duration prevents noisy alerts when hovering near zone thresholds.

Offline Neural AI Voices & System TTS: Choose between built-in Android system voices and high-fidelity, on-device neural AI models (Piper TTS). Includes a rich catalog of community voices, adjustable speech rate, voice downloads, and direct GitHub/HuggingFace model discovery.

Universal BLE Heart Rate Monitor Support: Connects seamlessly via Bluetooth Low Energy (BLE) with standard heart rate monitors and chest straps, including Polar H10 / H9 / Verity Sense, Garmin HRM-Pro / Dual, Wahoo TICKR, Scosche Rhythm+, and many more.

Reliable Off-Wrist & Disconnect Handling: Smart sensor watchdog immediately resets heart rate readings when your strap is removed or disconnected, preventing stuck or misleading data.

Customizable Heart Rate Zones: Set your custom target BPM ranges (e.g., Warm Up, Fat Burn / Aerobic, Cardio, Threshold, Max) to match your fitness goals.

Workout Simulator: Test voice announcements, zone thresholds, and dwell intervals anytime with the built-in manual heart rate simulator.

100% Private & Offline: All heart rate processing and AI speech synthesis run entirely on your device. No cloud streaming, no account required, and no telemetry tracking.

Battery-Efficient Background Service: Runs cleanly in the background with a persistent workout notification while you use your favorite GPS tracker, podcast app, or music player.