Privacy policy
Ichnos is an Android app that explains the health data your watch and phone record. This policy covers the Ichnos app and applies to every user.
The short version
Everything Ichnos does happens on your phone. Ichnos has no account and no server. It contains no analytics, advertising or tracking code, and it does not send your health data to the developer or to anyone else.
What Ichnos reads, and why
With your permission, Ichnos reads these data types from Health Connect, Android's health data store:
- heart rate, resting heart rate and heart rate variability
- sleep
- steps, distance and exercise sessions
- active and total calories burned
- weight and body fat
- oxygen saturation
- menstruation (period dates), only if you choose to allow it: they are used only so your resting heart rate is compared with the same phase of earlier cycles
It uses them only to show your trends, your recovery, your sleep, your training and your body composition, each compared with your own history. Ichnos only reads Health Connect: it never writes, changes or deletes anything there. You can remove any permission at any time in Health Connect's settings.
Ichnos also stores what you enter yourself in the app:
- your profile (birth date, height, sex, units)
- your journal and check-ins
- bloodwork results you type in or import from a PDF you choose
Where your data is kept
On your phone, in Ichnos's private storage, which other apps cannot read. The developer has no copy. Ichnos calculates everything inside the app: it runs no server, not even one on the phone itself, so no other app can ask it for your data.
- Android backup to your Google account: off unless you turn it on (More → Privacy). When on, Android includes your profile, journal, check-ins, bloodwork and experiments in its backup, encrypted end to end with your screen lock and controlled by Android and Google, not by Ichnos. Moving to a new phone directly (cable or Wi-Fi) works either way.
- Backup files. If you choose Save a backup file, Ichnos writes one file to the place you pick. That file contains your health data, so keep it private.
What leaves your phone
Nothing is sent automatically. Data leaves your phone only when you choose it, and each time is listed in the app under More → Privacy → "What left your phone", with exactly what was handed over:
- Feedback. "Send feedback" opens your own email app with a message to [email protected]. It contains what you wrote, plus the app version, your phone model and whether Health Connect is connected. It contains no health values. You see the email and decide whether to send it.
- Hevy (optional). If you connect Hevy with your own API key, Ichnos downloads your workouts from Hevy. Only the key is sent, and only to Hevy. Nothing about your health is sent.
- Ask your AI. If you use it, Ichnos writes a summary of the data you select, shows it to you in full, and hands it through Android's share sheet to the app you choose (for example ChatGPT, Claude or Gemini). That app's own privacy policy then applies.
- Sharing. If you share an experiment result, Android's share sheet hands the text you see to the app you choose.
- A backup file you save goes where you choose (for example Google Drive), and holds your health data.
Children
Ichnos is not intended for children under 16.
Deleting your data
Uninstalling Ichnos deletes everything it stored on your phone. Data in Health Connect, and in your watch's own app, is not affected. Backup files you saved stay where you put them until you delete them.
Not medical advice
Ichnos describes your data against your own normal. It is not a medical device, and it does not diagnose or treat anything.
This website
This website sets no cookies and runs no analytics. The interactive demos run in your browser; nothing you type into them is sent anywhere.
Changes
If this policy changes, the new version is published at this address with a new effective date.