Read the traces
your days leave.

Your watch records every night. Ichnos compares each one with your own normal and tells you what it means for today, with the reason beside every number. All of it is calculated on your phone.

Join the Android beta See a week
  • No account
  • No server
  • No analytics
  • Reads Health Connect, never writes

OVERNIGHT HRV · 60 NIGHTS

Made-up person

A TYPICAL SCORE

68

Readiness. No reason given.

ICHNOS

Steady

Any watch that syncs to Health Connect. Samsung, Pixel and Fitbit, Garmin, Xiaomi, Amazfit, Polar, Suunto, Withings, Oura, and Huawei through Health Sync.

A WEEK WITH ICHNOS

Seven mornings,
read against your own normal.

Step through one made-up week. Each morning gets one verdict and the reason for it, and the evenings you log start to explain the nights.

MONDAY · RECOVERY

Recovered

HRV, MS

SLEEP, HOURS

Monday

Every signal sits inside your usual range, so the verdict is simple: a hard session is on the table. You do intervals.

Intervals, 45 min

Tuesday

HRV dips a little and your legs are still recovering from Monday. Not a red flag, just a reason to keep something back.

Easy walk

Wednesday

Back inside your range. In the evening you log a coffee at five, because the meeting ran late.

Coffee at 17:00

Thursday

You slept an hour and a quarter less than usual and took 45 minutes to fall asleep. One night proves nothing about the coffee, so Ichnos only notes it. Friends call: drinks tonight.

Drinks with friends

Friday

HRV is far below your normal and your resting heart rate is up 6 bpm. Strained: keep it easy.

Ichnos has seen this before. After evenings with alcohol, your HRV the next morning is 18% lower, in 6 of the 6 times you logged it.

Rest day

Saturday

A long night of sleep pays some of it back. HRV is close to your range again, so a steady day.

Long walk

Sunday

Back to normal. One question is left: did Wednesday's coffee cost you that sleep, or was it a coincidence?

Test it on yourself. Ichnos picks 14 random evenings for a late coffee and 14 without, then gives one verdict from your own nights: likely real, or not shown.

1 / 7

INSIDE THE APP

Everything your watch records,
finally explained.

Today screen: the recovery verdict and the daily log
TodayYour verdict, how hard to go, and a thirty-second check-in.
Sleep screen: last night with its stages
SleepLast night against your usual nights, with timing and stages.
Journal screen: a week of mornings
JournalLog how you feel. Ichnos links it to your nights and mornings.
Experiment result: caffeine cut-off, likely real
ExperimentsTest a habit on yourself with randomised nights and one verdict.
Muscles screen: a body map of trained muscle groups
Training and musclesEvery sport in one log, and where your sets land.
Body screen: fat and lean mass over 90 days
BodyThe trend beneath the scale's noise, split into fat and lean.
Bloodwork screen: a lab draw with its markers
BloodworkImport a lab PDF, keep every marker's history.

TRY IT · BLOODWORK

Did it really change,
or is it just noise?

Two lab results almost never match, even when nothing changed: your body varies from week to week and so does the lab. Ichnos tells you when a difference is bigger than both.

TWO DRAWS, SAME LAB

Nothing you type leaves this page.

How this is worked out

The reference change value (Fraser, 2011): with the within-person variation CVI from the EFLM Biological Variation Database and lab imprecision CVA assumed at 0.5 × CVI, a change is outside normal variation when it lies beyond exp(±1.96·√2·σ) − 1, where σ = √ln(1 + CV²) and CV² = CVA² + CVI². Results from different labs are not compared. This describes your numbers and does not diagnose anything.

PRIVATE BY DESIGN

Your health data
stays on your phone.

No account

No sign-up, no email, no cloud profile, no advertising ID.

Calculated on the phone

Every number is worked out inside the app. There is no Ichnos server to send it to.

Read only

Ichnos reads Health Connect and never writes to it or changes your watch app's data.

A log of what left

Only what you share leaves, and the Privacy page lists every time it did.

This website has no cookies and no analytics either. Privacy policy

ANDROID BETA

Help shape Ichnos
before it launches.

The beta runs through Google Play's own testing programme, so you install and update Ichnos from the Play Store like any other app.

  1. Join the testers group

    One click with your Google account. The group is how Play knows you may install the beta, and members get one email when it opens.

  2. Opt in on Google Play

    Open the test link and tap "Become a tester".

  3. Install and connect

    Install from the Play Store, then let Ichnos read Health Connect. Your history appears in minutes.

QUESTIONS

Before you ask

Which watches work?

Any watch whose app writes to Health Connect on Android: Samsung, Pixel and Fitbit, Garmin, Xiaomi, Amazfit, Polar, Suunto, Withings and Oura, among others. Huawei watches work through the Health Sync app. Hevy is supported for gym sets.

Is there an iPhone version?

No. Ichnos is built on Health Connect, which is Android only.

Where does my data go?

Nowhere unless you send it. Ichnos runs entirely on your phone. Android's backup to your Google account stays off unless you turn it on, and you can save your own backup file.

Is it a medical device?

No. Ichnos describes your data against your own normal. It does not diagnose, treat or prevent any condition.

Who makes it?

An engineer and researcher who wanted his own watch data explained honestly: every number with its method one tap away, and what was not recorded shown as unknown, never as zero.