Luna privacy policy

Last updated: 31 October 2026

Luna is a period, fertility, intimacy and pregnancy tracker published by Bluedot Technology Ltd ("we", "us"). This policy explains what Luna does with your information. The short version is that Luna keeps it on your phone and we never receive it.

What Luna stores

Everything you enter is saved in the app's private storage on your device:

1. period start and end dates
2. birth control pill days
3. intimacy entries: date, protection method, activity types and an optional note
4. pregnancy start date, if you track a pregnancy
5. your settings: cycle length, period length, reminder times and choices
6. your app lock: the lock method, a random salt and a hash of your PIN
7. small bookkeeping values, such as whether the welcome setup has been completed and when the rating question may be shown again

Luna does not collect your name, email address, phone number, contacts, location, photos or advertising identifier.

What Luna sends

Nothing. The app is built without the Android INTERNET permission, so it cannot open a network connection at all. There is no account, no analytics, no crash reporting and no advertising SDK.

Two actions leave the app, only when you start them yourself:

1. Rate on Google Play opens the Play Store listing for Luna. Google handles that page under its own privacy policy.
2. Send the note in the rating dialog hands a pre-written email to your own mail app. You see and send the message yourself; we only receive it if you press send.

Backups

You can export all of Luna's data to a single JSON file. You choose the location with the Android file picker, and the file belongs to you. Luna cannot read it back unless you import it. If you share that file with anyone, they can read it, so keep it somewhere safe.

The app lock

If you turn on the app lock, your PIN is stored only as a salted PBKDF2-HMAC-SHA256 hash, and the PIN itself is never written to disk. Device unlock hands over to Android's own biometric or screen lock prompt; Luna never sees your fingerprint, face or device PIN. The lock is a screen cover inside the app, not full encryption of the device or of the stored file. The lock settings are deliberately left out of backups.

Deleting your data

You are in control at all times:

1. Delete individual entries inside the app.
2. Tap Clear all data in Settings to erase every record on that device.
3. Uninstall the app, which removes its private storage.

Because we never receive your data, there is nothing for us to delete on our side.

Children and the Play Families policy

Luna is meant for adults and is not directed at children under 13. We do not knowingly collect information from children, and the app has no account, no ads, no advertising identifier and no analytics.

Bluedot Technology Ltd is committed to follow the Google Play Families policy. Luna contains no behavioural or interest based advertising, shows no ads at all, and the only data it handles is the information you type in, kept on your device.

Your rights

Since the data never leaves your device, you exercise your rights directly: you can view, correct, export and delete everything from inside the app. If you are in a region with additional rights, for example under the GDPR, this design means there is no personal data for us to process.

Changes to this policy

If a future version of Luna changes how data is handled, this policy will be updated before that version is published, and the date at the top will change.

Contact

Bluedot Technology Ltd

Email: info@bluedot.ltd

Website: https://bluedot.ltd

Health disclaimer

Luna is not a medical device and does not diagnose, treat or prevent any condition. Predictions are estimates based on the dates you log. For contraception, cycle problems or pregnancy care, speak to a qualified clinician.