HRVSpark – Raw SDNN HRV data displayed on your Apple Watch

Summary: HRVSpark displays raw Heart Rate Variability (HRV) SDNN values as live sparklines and gauges directly on the Apple Watch face across four time windows. It avoids algorithmic interpretation, providing continuous, visible access to granular HRV data without scores or labels, enabling users to track physiological changes in real time.

What it does

HRVSpark shows raw HRV SDNN data from HealthKit on Apple Watch complications, updating live with sparklines and gauges over multiple time frames. It functions independently or alongside other HRV analysis apps, emphasizing direct data visualization rather than algorithmic summaries.

Who it's for

It is designed for Apple Watch users who prefer direct access to raw HRV data, including those monitoring conditions like arrhythmia or anxiety, and those who want to observe physiological responses without algorithmic interpretation.

Why it matters

By presenting unprocessed HRV data continuously on the wrist, HRVSpark helps users identify personal physiological patterns and responses without relying on potentially ambiguous algorithmic scores.