Privacy policy

The Ahlina · Cycle app and the family account. Last updated: 18 October 2026. Draft pending legal review

1. Who we are

The app is published by [legal entity], [address], [country]. Privacy contact: privacy@ahlina.app.

2. What stays on your phone

Everything you log is stored on your phone only, in a database encrypted with a random key kept in the system keystore (Android Keystore):

• Period start and end dates.
• Daily logs: flow, pain, mood, symptoms and notes.
• Your year of birth (not the full date), to show age-appropriate content.
• Your settings: language, consents, usual cycle length, app lock.

This data is not sent to us or to anyone else. The app works fully without an account and without internet.

3. The optional family account

An account is needed for two things only: sharing period dates with a family member you choose, and a cloud backup. If you create one, our servers hold:

• A masked login identifier: a keyed hash (HMAC) of your e-mail or phone number. We do not store the e-mail or number itself. It is used to send your sign-in code and to recognise you when you return.
• Your public key for encryption, the name you show your family if you set one, and your language.
• Sessions: a hash of the session token and its expiry (30 days).
• Family: who belongs to which family, and invite codes (valid 48 hours).
• Sharing: who shares what with whom, a log of view times, and the encrypted summary itself.
• The encrypted backup if you upload one.

Shared summaries and backups are encrypted on your phone before they leave it: the summary with the recipient's public key, the backup with a passphrase you choose. Our servers store ciphertext they cannot read. If you forget the backup passphrase, we cannot recover it for you.

4. What we do not do

• No ads, ad networks, trackers, third-party analytics, or crash reporters that send identifiers.
• We do not sell, rent or share your data for marketing.
• We do not ask for location, contacts, photos, or access to other apps.
• We do not use your data to train AI systems.

5. Legal basis

Cycle data is health data. We process it on the basis of your explicit consent, given at first setup (required for the app to work, since without local storage there is no tracking), with separate consents for reminders, sharing and backup. You can withdraw any consent in Settings at any time; withdrawing is as easy as giving.

6. Minors

• The app is for ages 13 and up. The age gate is neutral and gives no hint of the answer.
• Under 18, the app shows no fertile window or ovulation.
• Sharing with family belongs to the data owner alone: a parent's account has no button to request it, the daughter can stop it with one tap, both see that sharing is on, and every view of the summary is logged.
• Where the law requires parental consent below a given age, we ask for it before creating the account.

7. Sharing with others

We share your data with nobody, except providers acting on our instructions to run the service:

• Hosting: our servers are with [hosting provider] in [country]. Account data (not your phone's data) is stored there.
• Sign-in codes: an e-mail or SMS provider receives your e-mail or number to deliver the code only.

We may disclose data if the law obliges us to; in that case we hold only what section 3 lists, and we hold no keys to decrypt summaries or backups.

8. Retention

• Sign-in codes: 10 minutes, then void.
• Sessions: 30 days, or until you sign out.
• Invite codes: 48 hours or until used.
• Encrypted summary: deleted the moment sharing is turned off.
• The account and everything tied to it: until you delete it. Deletion is immediate.
• Server logs: path, status and timing only, no user identifiers, for 14 days.

9. Your rights

At any time you can: access your data (all of it is on your phone; Settings shows what the account holds), export it (an encrypted backup), delete it (from Settings, or from the account deletion page without installing the app), withdraw consents, and complain to your country's data protection authority. We answer requests within 30 days at privacy@ahlina.app.

10. Security

The on-phone database is encrypted (ChaCha20-Poly1305). Server connections use HTTPS only. Shared summaries are encrypted with per-device X25519 keys, backups with Argon2id and XChaCha20-Poly1305. App lock with biometrics or the phone's code is available in Settings.

11. Not a medical device

The app informs and tracks. Estimates are estimates, not a method of contraception, and never replace a clinician. Articles list their sources and review date.

12. Changes

When this policy changes we publish the new version here with its date and tell you in the app if the change is material.