Hormetic

An honest tracker
for the sauna.

Real-time heat-dose zones on your Apple Watch. Every estimated value labeled honestly. No accounts. No analytics. Your data never leaves your device.

01 Warming Up Cyan
02 Approaching Amber
03 Activation Red

What it does

Logs each sauna session as a HealthKit workout. Estimates your heat-dose zone in real time from heart rate, ambient temperature, and wrist temperature drift. Shows your time in each zone, peak response, and the version of the algorithm that produced your score.

What makes it different

Most wellness apps wrap marketing language around vague metrics. Hormetic does the opposite. Every value the algorithm derives is labeled "Estimated" in the interface — you always know what was measured versus inferred. The math is documented and citable. Sessions record which version of the algorithm produced their values, and your history is never silently recomputed when the algorithm changes.

Privacy by architecture

No account. No signup. No server. No analytics. No third-party SDKs. No tracking identifiers. No ads. Your data lives on your device and nowhere else. This is not a marketing claim — there is no infrastructure to send your data to, by design. Read the full policy →

Status

Hormetic V1.0 is in TestFlight. App Store submission is in progress. For questions, beta access requests, or feedback: support →