HRVSpark

Thank you to all you watchers of HRV and RHR. Pro is $0.99 for Summer 2026: one-time purchase, no subscription.

HRVSpark puts your raw Heart Rate Variability data directly on your Apple Watch face as a beautiful, glowing sparkline complication.

WHAT YOU GET • Free 8-hour raw HRV sparkline complication with your latest SDNN reading • Pro 24-hour, 7-day, and 30-day complication views for broader context • Circular gauge and corner complications built for glanceable watch-face use • Clean iPhone companion app with live gallery, install guidance, and detail views

WHY RAW? Most HRV apps bury your data behind opaque "readiness scores" and color-coded stress labels. HRVSpark skips the interpretation layer entirely. You see the actual numbers — and over time, you build your own intuition about what your data means.

BUILT FOR YOUR WRIST HRVSpark is complication-first. It was designed from day one to live on your watch face, not behind an app icon. Glance at your wrist and immediately see your trend.

PAIR IT WITH RHRSpark Our sister app RHRSpark brings the same no-scores, no-verdicts philosophy to resting heart rate, giving you a complementary baseline view alongside HRVSpark.

SIMPLE, HONEST PRICING Free to try with a one-time Pro unlock. No subscriptions. No tracking. No ads. Ever.