Observed arrival · 2026-08-29
Calmline measures stress against your own baseline
An Apple Watch app that turns heart-rate variability into a personal stress score, calculated entirely on the device.
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$Paid
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✦Pretty
●Pro
◎Niche
◉Human
⚑Risk
ƒJS
Field notes
The app derives its score from the relationship between current HRV and a personal baseline, using the median of recent daily averages rather than a population norm. It waits for three usable days before producing a score and triggers only when a threshold is crossed, rather than repeatedly tapping the wrist. The page also describes sleep-aware sensitivity, four complication layouts, WorkoutKit recovery sessions, and CSV or JSON exports with units and the formula included.
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Editorial observations of this landing page, not a rating.
○OpenPublic substance visible
$PaidCommerce or pricing visible
✦PrettyNotable craft visible
●ProPolished or operationally mature
◎NicheUnusually specific use
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