Cysterly (“Cysterly,” “we,” “us”) is a wellness app that helps people with PCOS track symptoms, food, cycle, and weight, and discover patterns in their own logs. We built Cysterly to be private by design and to collect as little as possible. This policy explains what happens to your information.
1. Information stored on your device (not sent to us)
Almost everything you do in Cysterly is stored only in a database on your own phone. We do not operate a server that receives or stores it, and we cannot see it. This includes:
- Your symptoms, severity ratings, cycle and period entries
- Food entries, meal photos, tags and notes
- Weight entries and goals
- Sleep, stress, exercise, supplements
- The insights and trends Cysterly calculates from your logs
- Your settings, optional nickname, optional name for reports, streaks and rank
Because this data lives on your device, you are in control of it. If you delete the app, this data is removed with it.
2. Information we do not collect
We do not require you to create an account, and we do not collect your name, email address, phone number, or password to use the app. There is no cloud login and no automatic sync of your health data to us or anyone else.
3. Optional features that send data off your device
A few features are turned off by default and only send data when you choose to enable and use them:
🍽️ AI meal recognition & calorie estimates
If you enable this and tap to analyze a meal photo, that photo is sent over an encrypted (HTTPS) connection to our secure processing service and then to our AI provider (Anthropic, maker of Claude) to suggest a food name, tags, and a rough calorie estimate. The photo is used only to generate that estimate, is processed transiently, is not used to train AI models, and is not stored by us.
✨ AI pattern summaries (“Ask Claude to explain”)
If you tap this, Cysterly sends short, already-summarized descriptions of the patterns found in your data (for example, “bloating tends to be higher on dairy days”) to the same AI provider to write a plain-language summary. Your raw logs, your name, and your identity are never sent — only these brief, de-identified pattern phrasings.
⛅ Weather in your daily forecast
If you enable weather, your approximate location (coordinates) is sent to a weather service (Open-Meteo) to fetch your local conditions. We use it only to show the weather and do not store your location.
4. Subscriptions & payments
Cysterly is a paid subscription. All purchases are processed by the Apple App Store or Google Play — we never see or receive your card or payment details. To check whether your subscription is active, we may use a subscription-management service (such as RevenueCat), which receives a random, anonymous app identifier and your store purchase receipt — never your health data.
5. Community features & your nickname
Cysterly may show a friendly streak “leaderboard.” If a live community leaderboard is offered, the only things ever shared are a nickname you choose and your streak number — never your symptoms, food, weight, or any health data. Participation is optional and you choose your nickname.
6. We never sell your data — and no ads
We do not sell or rent your information. We do not show advertising, we do not use advertising trackers, and we do not build an advertising profile of you. We do not use third-party advertising or analytics networks to track your behavior.
7. Third-party services we rely on
The optional and operational features above involve these providers, who each receive only the minimum described:
- Anthropic — AI food recognition & pattern summaries (only when you use them)
- Cloudflare — our secure processing service and website hosting
- Open-Meteo — weather (only if you enable it)
- Apple App Store / Google Play — app distribution and payments
- RevenueCat — verifying subscription status
8. How your information is protected
Data stored on your device is protected by your phone’s built-in security (such as your passcode, biometrics, and operating-system protections). Any data sent for the optional features above is transmitted over encrypted (HTTPS) connections.
9. Keeping, exporting & deleting your data
Because your data lives on your device, you control it:
- Export / back up: Settings → “Export / back up my data” saves a copy you control. There is no cloud backup, so please export before changing or wiping your phone.
- Delete: remove individual entries, use Settings → “Clear all data,” or delete the app to erase everything.
We have no server-side copy of your health data to delete, because we never received it.
10. Children
Cysterly is intended for adults and is not directed to children under 13 (or under 16 where required). If you are below that age, please do not use the app.
11. Your privacy rights
Depending on where you live (for example, under the GDPR or CCPA), you may have rights to access, correct, or delete personal information a company holds about you. Because we keep your health data on your own device and do not collect it on our servers, that data is already in your hands. For any questions about information processed through the optional features above, contact us using the details below.
12. International users
If you use the optional AI or weather features, the data described may be processed on servers located in the United States or other countries. By enabling those features, you consent to that processing.
13. Changes to this policy
We may update this policy from time to time. When we do, we’ll post the new version here and update the “Last updated” date above. Significant changes will be highlighted in the app or on this page.
14. Contact us
Questions about your privacy or this policy? Email us at [email protected] — we’re happy to help.
A note on health: Cysterly is a wellness and self-tracking tool. It is not a medical or diagnostic device, it does not provide medical advice, and it does not diagnose, treat, or determine the cause of PCOS or any condition. Always consult a qualified healthcare professional about your health.