Joel Farthing

Joel Farthing

Filament Labs: A Window, not a Verdict
#95085881 follower8 following
>10,000All time
3 KP

About

Tools for the data-curious. Currently building HRVSpark — raw HRV sparklines on your wrist.

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Maker History

  • RHRSpark
    RHRSparkYour resting heart rate. Raw. Beautiful. On your wrist.
    Apr 2026
  • HRVSpark
    HRVSparkYour HRV. Raw. Beautiful. On your wrist.
    Mar 2026
    • 🎉
    Joined Product HuntMarch 3rd, 2026

Forums

Joel Farthing•

2mo ago

RHRSpark - Your resting heart rate. Raw. Beautiful. On your wrist.

RHRSpark is a transparent resting heart rate app for Apple Watch that displays sedentary HR and Apple's daily RHR as live sparkline complications. Ten watch face complications. No scores, no interpretation. $2.99 one-time Pro unlock. No subscription. From the maker of HRVSpark.
Joel Farthing•

3mo ago

HRVSpark - Your HRV. Raw. Beautiful. On your wrist.

The usual HRV app flow: data → algorithm → verdict → user. HRVSpark reverses it: data → user → intuition. Raw SDNN sparklines and gauges on your Apple Watch face, across four time windows. Complication-first — always visible, never buried in an app. Works alongside analysis suites like Athlytic or HRV4Training, or stands alone as your only HRV tool. $2.99 one-time. No subscription. No account.
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