Description

Sentinel is an experimental, on-watch wellness monitor for Pebble Time 2.

Enable background monitoring once, then keep using your normal watchface. Sentinel attempts short overnight heart-rate and optical pulse-interval recordings, rejects unsuitable motion-contaminated data, and builds a personal baseline over qualifying nights.

Features:
- On-watch dashboard with monitoring status, heart rate, RMSSD when available, sample freshness and calibration progress.
- Recent-night heart-rate and HRV history, with missing measurements shown as gaps.
- Configurable night hours, recording cadence, window duration and notification settings.
- Experimental strain notices for sustained changes from your own baseline. The background worker opens Sentinel once for an eligible episode; the app vibrates unless Quiet Time is active. Muted/silent notices remain in the app. This is not a native phone push notification.
- No account, network connection or maintainer server required by Sentinel. Measurements stay on the watch. Any optional Pebble Health platform synchronization is controlled by PebbleOS, not this app.

IMPORTANT: This is an early experimental release, not a medical device. It cannot diagnose illness, estimate your probability of infection, rule illness out or replace medical advice. Poor sleep, exercise, alcohol, stress and other factors can change the readings. Real-watch HRV quality, overnight coverage and battery impact have not yet been validated. The worker has limited memory headroom; this release is for testing, not dependable health surveillance.

Current Pebble Time 2 only, with firmware supporting SDK 4.33 HRV APIs. Pebble 2 Duo and Round 2 do not have the required heart-rate sensor. Only one third-party background worker can run: another background app can replace Sentinel. After a reboot or interruption, check monitoring status and restart it if needed. Frequent recordings use more battery.

SpO2 is not supported in this release. An unavailable placeholder is not an oxygen measurement. Trust symptoms and appropriate medical advice, not a normal app status.