Privacy policy

Last updated: 9 October 2026

In short

Cyclia keeps everything you enter on your own phone. There is no account, the app has no access to the internet, and nothing is sent to us or to anyone else. We cannot see your data.

Who is responsible

Cyclia is published by Adrian Overdijk. Questions about this policy can be sent to cyclia@appswithmanners.com.

What the app stores, and where

Cyclia stores what you enter yourself:

• your first name, if you enter it; this is optional
• your year of birth, if you enter it; this is optional
• period days and flow
• symptoms and moods
• fertility signs: basal body temperature, cervical mucus, ovulation tests
• intimacy, pill use, other medication and notes
• your settings, such as cycle length, whether your cycles are irregular, theme, language and reminders

All of this is stored only on your phone, in a database that is encrypted. The key is kept in the secure key storage of Android. If you switch on the app lock, your PIN is stored as a one-way hash, not as the PIN itself.

What the app does not do

• It does not ask for an account or an e-mail address. Entering your first name is optional.
• It has no permission to use the internet, so it cannot send data anywhere.
• It contains no advertising, no analytics and no trackers.
• It does not share or sell data. There is no data with us to share.
• It is left out of Android's automatic backup and device transfer, so your data is not copied to a cloud account without you doing it yourself.

Permissions

• Notifications: only asked when you switch on a reminder. Reminders are made on your phone; no server is involved.
• Fingerprint or face unlock: only used if you switch it on for the app lock. Android checks your fingerprint or face. Cyclia only hears whether it matched.

Backups, exports and the doctor report

You can make a backup, an export or a report yourself. These are files that you save where you choose.

• A backup is encrypted with a passphrase you choose. Without that passphrase nobody can read it, and it cannot be recovered if you forget it.
• An export (CSV or JSON) and the doctor report (PDF) are not encrypted. Anyone who gets the file can read it.

Once a file is saved outside the app, for example in a cloud storage service, the terms and privacy policy of that service apply to it.

Deleting your data

"Delete all my data" in the app removes everything you entered and all settings. Removing the app from your phone does the same. Files you saved yourself, such as backups and exports, are not removed by this; delete those where you saved them.

This website

This website uses no cookies, no analytics and no trackers, and loads nothing from other websites. The site is hosted by Cloudflare. As with any website, the hosting provider processes technical data to show the page, such as your IP address. We do not look at or keep that data ourselves.

If you send us an e-mail, we use your e-mail address and your message only to answer you and, if it is feedback, to improve the app.

Children

Cyclia is not aimed at children under 13.

Not a medical device

Cyclia's predictions are estimates based on what you logged. Cyclia is not a contraceptive method and not a medical device, and it does not replace advice from a doctor.

Changes

If this policy changes, the new version is published on this page with a new date.