Cycle tracking. Privately.
No accounts. No ads. No server. Your data never leaves your device. Open source and verifiable.
Built for every stage of life
Clio Daye started as a privacy-first menstrual cycle tracker — but the people who need it most aren’t only in their reproductive years. We expanded the app to support the full hormonal journey, from first periods through perimenopause and into menopause, because these transitions are underserved by mainstream health apps and carry even greater privacy stakes.
Menstrual tracking
Log cycles, symptoms, mood, and flow. Predict windows with on-device intelligence — no cloud required.
Perimenopause
Track irregular cycles, hot flashes, sleep disruption, and the full range of early and late perimenopausal symptoms.
Menopause
Log and monitor post-menopausal symptoms over time. Your history stays private and always accessible.
Available worldwide
Clio Daye is fully internationalized — the app is localized for multiple languages and regions, with date formats, units, and terminology adapted for each locale. Health is not a US-only concern.
Privacy by design
On-device only
All your data stays on your iPhone. Nothing is sent to any server — ever.
No account required
No email. No sign-up. No tracking. Open the app and start — that’s it.
Face ID protected
Lock the app with Face ID or Touch ID. Your health data is yours alone.
Open source
Fully auditable. Review the code, verify our claims, or fork it yourself.
Why privacy matters here
Period and cycle data is among the most sensitive health information you can share. In many jurisdictions it can carry legal risk. Clio Daye was built on a simple premise: this data should never leave your device, and you should be able to verify that claim yourself.
Unlike apps that require accounts and sync to the cloud, Clio Daye uses Apple’s on-device frameworks. No analytics, no advertising SDKs, no third-party data brokers. What you log stays with you — across every stage of life.
Fully open source · MIT licensed
Source code on GitHub. Read it, audit it, fork it.