Effective August 12, 2026

Privacy Policy

Caelyn is built so your cycle data stays on your device. This policy explains exactly what that means, what little information we may receive, and the rights you have over your data.

Plain‑English summary. Caelyn does not collect, sell, or share your cycle entries, symptoms, moods, notes, or any other health information, and we run no servers of our own. There are no analytics SDKs, no advertising trackers, and no third‑party data brokers in the app. Your cycle history lives in a private database on your device. If you switch on iCloud Sync, a copy is also kept in your own private iCloud — Apple's storage, tied to your Apple Account, which we cannot read and never receive. Sync is off unless you turn it on, and you can permanently delete the iCloud copy from inside the app at any time. There is still no Caelyn server and no Caelyn copy of your history.

1. Who we are

Caelyn ("Caelyn," "we," "us," or "our") is an iOS app published by an independent developer. References to "the app" mean the Caelyn iOS application. References to "you" or "your" mean the person using the app.

If you have a question about this policy, email rajesh.panta08@gmail.com.

2. Information we do not collect

We want to be specific about what does not happen, because it is the unusual thing about Caelyn:

We do not collect your cycle entries, period dates, flow levels, symptoms, mood check‑ins, pain logs, medication entries, or notes.
We do not collect your email address or phone number. If you sign in with Apple, Caelyn asks Apple only for your name — never your email — and the only thing it keeps is an anonymous identifier Apple generates for this app. If you use Hide My Email, no relay address is created for Caelyn, because Caelyn does not ask for one.
The name Caelyn greets you by is one you type and confirm. It is stored on your device (and in your own iCloud if you enable sync), never sent to us.
We do not collect your device identifier (IDFA), advertising ID, IP address, location, contacts, photos, or microphone input.
We do not use third‑party analytics (no Google Analytics, no Firebase Analytics, no Mixpanel, no Amplitude, no Segment, no Sentry, etc.).
We do not use advertising networks or behavioral tracking of any kind.
We do not sell, rent, or share any personal information, because we do not collect any.

3. Information that stays on your device

Everything you log in Caelyn is stored locally in an on‑device database (Apple's SwiftData / Core Data) in your app's private container. This includes:

Cycle entries (period start dates, flow level, symptoms, mood, pain, medication, notes).
Your profile preferences (cycle length, period length, reminders, app lock setting, first day of week).
App settings such as private‑notification mode and hide‑preview mode.

This data is sandboxed by iOS — no other app on your device can read it. Caelyn does not back this database up to any server we control.

If you have iCloud Backup enabled in iOS Settings, Apple may include the app's container in your encrypted iCloud backup. That backup is controlled by Apple and your Apple ID, not by Caelyn. You can review or disable this in iOS Settings → [your name] → iCloud → iCloud Backup.

4. iCloud Sync — optional, and your iCloud, not ours

Caelyn can keep your history available across your Apple devices using your own private iCloud database. It is off until you switch it on in Settings → Account & iCloud.

The copy lives in your personal iCloud account, in a private database only you can reach. It is Apple's storage, governed by Apple's privacy policy and your Apple Account.
We never receive it and cannot read it. Caelyn still runs no servers. Nothing is stored in a public or shared iCloud database, ever.
With sync off, nothing about your cycle leaves the device apart from what you explicitly export or share with Apple Health. Deleting the app then deletes your history with it, so Settings → Export data is your backup.
You can permanently delete the iCloud copy at any time: Settings → Account & iCloud → Delete my iCloud copy. That removes the cloud copy and leaves everything on your device untouched. Turning sync off on its own does not remove a copy already made — the delete action stays available for exactly that reason.
Settings → Delete all data asks whether you mean this device only, or this device and the iCloud copy.
Some things deliberately never sync, because they belong to one device: your app lock PIN, your Apple Health connection and permissions, and the position Caelyn has reached when reading from Apple Health.

4a. Signing in with Apple — optional

Caelyn offers Sign in with Apple purely for identity and personalization. It is never required. Every feature works signed out, and your cycle history exists whether or not you ever sign in.

Caelyn requests your name only. It does not request your email address.
Apple gives the name once, on the first authorization. Caelyn treats it as a suggestion and asks what you would like to be called; the name you confirm is the one used.
The only credential kept is Apple's anonymous per-app identifier, stored in the device Keychain and marked so it never travels to another device.
Signing out never deletes anything. Neither does deleting your Caelyn account — that removes the Apple sign-in and nothing else. Deleting your history is a separate, clearly-labelled choice, because losing an account should never mean losing years of tracking.
Deleting your Caelyn account does not cancel a Caelyn Pro subscription. Apple bills that, and it continues until you cancel it with Apple.

5. Apple HealthKit

Caelyn integrates with Apple Health (HealthKit) only if you explicitly opt in from Settings → Apple Health. When you do:

iOS shows you the standard HealthKit permission sheet, where you choose which categories Caelyn can read or write.
Caelyn can read menstrual-flow history and Apple Watch sleeping wrist temperature, and can write menstrual flow, symptoms, and pain that you log in Caelyn.
Caelyn reads and writes data through Apple's HealthKit framework on your device. We never receive a copy on any server.
You can revoke any HealthKit permission at any time in iOS Settings → Health → Data Access & Devices → Caelyn.

HealthKit data is governed by Apple's privacy controls and your device passcode/biometrics. Caelyn never transmits your HealthKit data outside your device.

6. Notifications

Local reminders — such as period, ovulation, daily check‑in, medication, birth‑control, and your own note‑to‑self reminders — are scheduled by the app on your device through Apple's local notification system. Nothing about these reminders is sent to a server. The text of a personal note is never placed on your lock screen. If you enable "Private notifications" in Settings, the lock‑screen text is replaced with a generic "Caelyn reminder" so a glance reveals nothing about your cycle.

7. Subscriptions and payments

Caelyn Pro is available as an auto‑renewable monthly subscription (with a seven day free trial) or yearly subscription, or a one‑time lifetime purchase, sold through Apple's In‑App Purchase system, and may be shared through Apple Family Sharing. When you buy:

Apple — not Caelyn — processes your payment, billing, and renewal. We never see your credit card number, billing address, Apple ID password, or other payment details.
Apple shares with us a transaction identifier and the product ID you purchased so the app can verify your entitlement on this device. This transaction identifier is not tied to your name or email by Caelyn.
You can manage or cancel your subscription at any time in iOS Settings → [your name] → Subscriptions.

Apple's privacy practices around the App Store and In‑App Purchase are described at apple.com/legal/privacy.

8. Crash reports and diagnostics

Caelyn does not include a third‑party crash reporting SDK. If you have iOS Analytics turned on (Settings → Privacy & Security → Analytics & Improvements → Share With App Developers), Apple may share an aggregated, anonymized crash log with the developer. That data is controlled and anonymized by Apple before we ever see it; it is not linked to your name, email, or cycle data. You can turn it off in iOS Settings at any time.

9. Children's privacy

Caelyn is rated 12+ on the App Store and is not directed at children under 13. We do not knowingly collect personal information from children under 13 — and because we do not collect personal information from anyone, this commitment is straightforward. If you are a parent or guardian and believe a child under 13 has been using Caelyn, you can delete the app to remove all on‑device data.

10. Your rights

Because your cycle data lives on your device — and, if you enable sync, in your own iCloud rather than on any server of ours — you have direct, immediate control over it without needing to ask us:

Access: open the app to view all data we hold; use Settings → Export data to generate a CSV (or PDF on Pro) of every entry.
Correction: edit any entry in the Calendar or Log tab.
Deletion: Settings → Delete all data wipes every entry, your profile, and your settings, and asks whether you mean this device only or the iCloud copy as well. Settings → Account & iCloud → Delete my iCloud copy removes the cloud copy on its own, leaving the device untouched. Deleting the app removes everything on the device — but not an iCloud copy you have already made, so delete that first if you want it gone.
Portability: the CSV export is a standard, portable format that can be opened by any spreadsheet app or imported into another tracker.

If you are in the European Economic Area, the United Kingdom, or Switzerland, the GDPR gives you these rights as a matter of law. If you are a California resident, the CCPA / CPRA gives you analogous rights, including the right to know, the right to delete, and the right to non‑discrimination. We do not sell or share personal information as those terms are defined in the CCPA / CPRA. For any rights request you cannot fulfil yourself in‑app, email rajesh.panta08@gmail.com.

11. International users

Caelyn is offered worldwide through the Apple App Store. Because the app does not transmit your cycle data to any server we control, there is no cross‑border transfer of your personal data by us. Apple's payment processing for subscriptions may involve cross‑border transfer governed by Apple's own privacy policy.

12. Security

Your cycle data lives in iOS's per‑app sandbox and benefits from the device‑level encryption iOS applies when your device is locked with a passcode or biometric. Caelyn additionally offers an in‑app lock (Face ID / Touch ID) and an optional app PIN, which you can enable in Settings → Privacy. If you set a PIN, only a salted hash of it is stored in the device Keychain — never the PIN itself.

For higher‑risk situations, Caelyn offers optional features you control: a duress PIN that, if entered instead of your normal one, silently and permanently erases all Caelyn data; an "auto‑erase if inactive" option; and "Delete all data," which removes every entry, your profile, and the data Caelyn wrote to Apple Health.

Because we do not operate a server containing your cycle data, there is no server‑side breach scenario for that data. The risks that remain are device theft, malware on your device, and your iCloud Backup security — all of which are controlled by Apple's platform security and your Apple Account, not by us.

13. Changes to this policy

If we change this policy, we will update the "Effective" date at the top of this page and, for material changes, update the version inside the app. Continued use of Caelyn after an update means you accept the revised policy.

14. Contact

For privacy questions, data requests, or anything else: rajesh.panta08@gmail.com.