This period tracker learns your unique cycle patterns and keeps all your health data private on your device. It offers detailed insights into your cycle, symptoms, and mood, with robust privacy features and an optional Pro version for advanced analytics.
1.3
August 30, 2026
You can now create an optional Caelyn account with Sign in with Apple, and turn on private iCloud sync so your cycle history is already there when you set up a new device, nothing to export, nothing to retype. Caelyn can also learn what to call you, so it greets you by name instead of saying nothing at all. All of it is optional. Caelyn works exactly the same without signing in, nothing is locked behind an account, and your history syncs only to your own private iCloud, never to a server anyone else can read. Signing out keeps your history. Deleting your account, deleting your iCloud copy, and deleting your data are three separate choices, each with its own confirmation. This update also improves reliability and data protection throughout.
MoreFull insights, charts and PDF reports.
$99.99
Pro Lifetime
Every Pro feature, forever. One payment.
Caelyn focuses on learning your unique cycle patterns directly on your iPhone, rather than relying on averages. It prioritizes privacy by keeping all your health data locally stored, with no accounts or servers involved.
Yes, the core features of Caelyn are free. This includes unlimited logging, full predictions, calendar, reminders, five pattern insights, six months of your year in review, a home screen widget, Apple Health integration, app lock, and CSV export.
Caelyn Pro unlocks additional pattern insights beyond the first five, detailed charts for various cycle aspects, a full twelve months in review, a PDF export for doctors, and fertility tracking for conception, pregnancy, and postpartum.
Caelyn is built with privacy as a core principle. It makes no network calls, has no analytics, advertising, or third-party trackers. All entries are stored in a private database on your iPhone, and it offers features like Face ID/PIN lock and private notifications.
Yes, you can export your data as a CSV file at any time. Caelyn Pro also offers a clear PDF export of your history, which is useful for sharing with healthcare providers.
Yes, Caelyn integrates with Apple Health. This allows for seamless data sharing and a more comprehensive view of your health metrics.
The app was last updated on August 30, 2026, with version 1.3. This indicates a commitment to ongoing development and improvements.
Caelyn has an age rating of 12+. This suggests it is suitable for users aged 12 and above, covering a broad demographic interested in personal health tracking.
