This page answers the questions that come up most often about Nadir. If yours is not here: app@goswami.de. General matters are on the support page, data handling in the privacy policy.
Write to app@goswami.de. Please mention the app version (at the bottom of Settings), your iOS version and your device — and for Nadir, which watch you wear.
Nadir measures nothing itself — it reads what is already in Apple Health. That means it needs an Apple Watch worn overnight: the beat-to-beat intervals and the sleep analysis are recorded there.
Without a watch worn at night the metrics stay empty. That is not a malfunction, simply a missing basis to compute from.
Three causes are common. First, missing permissions: check Settings → Health permissions, which shows how many of the requested permissions are granted. You can grant them in the Health app under Data Access & Devices → Nadir.
Second, a night without the watch: a night with no usable heartbeat series deliberately gets no score rather than an interpolated one. Better a gap than an invented number.
Third, too little history: the comparison values need a run-up. Settings → Data quality shows how good the coverage is and where the values come from.
The metrics are not measured against a general norm but against your own rolling comparison values over 30 and 60 days. If your average shifts, so does the ranking — the same raw value can be scored differently. Trends shows both side by side.
Under Settings → Calibration you set your maximum heart rate and the weighting with which the partial scores combine. A wrong maximum heart rate distorts strain above all. If the arithmetic matters to you: Settings → Always show the maths expands the derivations everywhere, and the Glossary explains each metric on its own.
In the journal you record per night what happened the evening before — alcohol, a late meal, screen time, afternoon caffeine, travel, illness, sauna, stress. An entry belongs to the night that ends on that morning; tapping in the evening assigns it to the night ahead. The entries are voluntary, stay on the device and can be removed again at any time.
Nadir exports daily values as CSV and the underlying series as JSON, and hands the file to the share sheet — from there into Files, an email or a spreadsheet app.
The raw beat-to-beat intervals are not included. The app folds them into a single figure per night as it processes them and never keeps the individual heartbeats.
No. The app requests read permissions only and asks for no write access. Nothing from Nadir is left behind in Apple Health. The full list of what it reads is in the privacy policy.
Under Settings → Delete derived data you remove calibration, weighting and journal. Apple Health is never touched — your health data there stays as it is. On the next launch Nadir reads it again and recomputes.
Under Settings → Language Nadir can be set to English or German independently of the system; under Units you can switch between metric and imperial and between 24- and 12-hour display.
No. Nadir puts measurements from Apple Health into context and explains how it calculates. The figures are not a medical finding and do not replace medical advice. If a value worries you, talk to a doctor — not to an app.