Privacy policy
Last updated 31 October 2026
Moonbun is a period and cycle tracker made by Utterly Useless LLC. We built it so your health information stays with you. This page explains, in plain words, what Moonbun stores, where, and what you can do about it.
The short version
- Your logs (period days, flow, mood, energy, symptoms and notes) are stored only on your phone. We never receive them.
- You don't need an account, email or phone number to use Moonbun.
- If you choose to share with someone, only the summaries you switch on are sent to our server, and only that person can see them.
- No ads. No selling or renting data. No advertising or analytics tools. No tracking across apps.
- You can delete everything from inside the app at any time.
What stays on your phone
Everything you log, your settings, your companion and your passcode (stored only as a salted one-way hash) are kept in Moonbun's private storage on your device. They are excluded from cloud backups and device-to-device transfers. Uninstalling Moonbun or using Me › Erase everything on this phone deletes them. Use Me › Export everything first if you want a copy.
Sharing with a partner or friend (optional)
Sharing is off until you make an invite code. When you do, Moonbun creates an anonymous account on our server: no email, no password and no real name required. For each person you link with, we store:
| Data | Why | Who can see it |
|---|---|---|
| The first name or nickname each of you types | So you both know who you are linked with | You and the linked person |
| Only the summaries you switch on: your estimated period window and season, today's energy, today's mood, today's body symptoms | To show them on the other person's phone and send them a heads-up | Only the person it is shared with |
| Care packs (for example "a cookie"), with sender name and date | To deliver them | Sender and receiver |
| Invite codes (they expire after 7 days) | To link two phones | Nobody else |
| A random account ID | To keep each person's shared data separate | Nobody else |
Your notes, flow, full history and anything you have not switched on are never sent. You can pause sharing, change what is shared, or remove a person at any time; removing someone stops them seeing anything straight away. Sharing data is stored with our database provider Supabase on servers in the United States, encrypted in transit and at rest, and protected so each person can only read what was shared with them. Seen care packs are deleted after 180 days and expired invite codes every day.
Purchases
Moonbun Plus is a one-time purchase handled entirely by Google Play. We never see your card or payment details. Google's privacy policy applies to the purchase.
Notifications
Reminders are scheduled on your phone. On the lock screen they show only "Moonbun". You can turn each kind off in the app or in your phone's settings.
What we don't do
No sign-up, no ads, no analytics or crash-reporting tools, no access to your contacts, photos, camera, microphone or location, and we never sell or share data with advertisers or data brokers.
Children
Moonbun is for people aged 13 and over. It does not let anyone under 13 set it up, and we do not knowingly collect information from children under 13. If you think a child has given us information, email us and we'll remove it.
Deleting your data
- Shared data and your sharing account: in Moonbun, go to Me › Stop sharing and delete sharing data (or Me › Delete my sharing data on a partner's phone). This removes your links, shared summaries, care packs and the anonymous account from our server immediately.
- Everything on your phone: Me › Erase everything on this phone, or uninstall the app.
- No longer have the app? Email info@utterlyuselessllc.com with the subject "Moonbun data deletion", the first name you used and the name of the person you shared with. We delete the matching sharing data within 30 days and confirm by email.
Your rights
Depending on where you live (for example under the GDPR, UK GDPR or US state privacy laws such as the CCPA and Washington's My Health My Data Act) you can ask to access, correct or delete personal information about you, and to withdraw consent to sharing at any time. Email us and we'll help.
Medical note
Moonbun gives estimates, not medical advice. It is not a medical device and not a form of contraception.
Changes
If this policy changes we'll update this page and its date, and tell you in the app about important changes.
Contact
Utterly Useless LLC · info@utterlyuselessllc.com
Support
Questions, a bug or an idea? We usually reply within 2 working days at info@utterlyuselessllc.com.
Share with a partner or friend
On your phone: Together › Invite your partner (or best friend) and send the 6-letter code. On their phone: install Moonbun and tap Someone invited me? I have a code. You choose what they see in Me › Sharing.
Report a problem with someone you share with
You can remove anyone at any time in Me › Sharing › Remove (or Me › Stop following on a partner's phone). To report misuse, use Report next to their name or email us with the subject "Moonbun report". We review every report and can remove accounts that break our terms.
Restore Moonbun Plus
In the app: Me › See everything in Plus › Restore my purchase, signed in to Google Play with the same account you bought it with. Plus is a one-time purchase, so there is nothing to cancel.
New phone
For privacy, your logs are not backed up to the cloud. Before switching phones, use Me › Export everything, then on the new phone use Me › Bring history from Flo, Clue or a spreadsheet and pick that file.
Forgot your passcode
For your privacy there is no back door. Open your phone's Settings › Apps › Moonbun › Storage and clear the app's data. This erases your logs, so export them first if you can.
Notifications not arriving
Check Me › Notifications in Moonbun, then your phone's Settings › Apps › Moonbun › Notifications, and that battery saving isn't stopping Moonbun.