Cairn — Privacy Policy

Cairn keeps your readings on your device. The app never transmits your health data — not to Mossforge, not to anyone else. There is no account to create and nothing to sign in to.

Who this is about

Cairn (com.mossforge.cairn) is an Android app published by Mossforge, a one-person independent developer. This policy covers the Cairn app and this website.

What Cairn stores

Everything you enter is written to a database inside the app's private storage on your device:

• The readings you record — blood pressure, weight, blood glucose, body temperature and blood oxygen — and the date and time of each.
• The profile names and descriptions you create, if you log for more than one person.
• Your settings: units, clock format, theme, and which metrics you have chosen to show.

That is the whole list. Cairn does not ask for your name, email address, phone number, location, contacts, photos or any device identifier, and it has no way to read them.

What leaves your device

Three things can move data off your device. None of them is Cairn sending your readings somewhere, and all three are listed here so the picture is complete.

• Android's own backup. If you have Android Backup switched on for your device, the Android operating system copies Cairn's database and settings to your Google account, so a new phone can restore them. This is done by Android, not by Cairn, and it goes to your account — not to Mossforge. You can turn it off in your device's system settings, under Google › Backup.
• Files you choose to share. Cairn can export your readings as a CSV or a PDF. When you share one, Android hands the file to whichever app you pick — email, a messaging app, cloud storage — and what happens to it next is governed by that app, not by Cairn. Nothing is exported or shared unless you ask for it.
• Purchases. Cairn offers a one-time in-app purchase to unlock unlimited exports and additional profiles. Google Play handles the entire transaction; Cairn only asks Google Play whether a purchase exists for your account. Mossforge never sees your payment details, and no reading of yours is involved in a purchase.

What Cairn does not do

• No accounts, no sign-in, no user profiles held by Mossforge.
• No analytics, no telemetry, no crash reporting, no advertising, no third-party trackers.
• No selling or sharing of personal information — there is none collected to sell.
• No interpretation of your readings. Cairn records what you enter and performs plain arithmetic over it — averages, highest and lowest, a trend line. It does not tell you whether a reading is normal, high or concerning, and it is not a medical device. For anything about what your readings mean, talk to a clinician.

Deleting your data

Cairn's Settings screen can delete individual readings, everything of a single metric, or every reading it holds. Uninstalling the app removes its database along with it. If Android Backup has already copied your data to your Google account, remove that copy from your Google account's backup settings — Mossforge cannot reach it.

Children

Cairn is not directed at children and Mossforge does not knowingly collect anything from anyone. Because the app collects no data at all, it holds nothing about a child any more than it holds anything about an adult.

Changes to this policy

If Cairn's handling of your data ever changes, this page changes with it and the effective date above is updated. Material changes will also be noted in the app's release notes on Google Play.

Contact

Questions about this policy or about Cairn: privacy@mossforge.app.