Clio Daye

Your cycle data is yours. We mean that literally.

Most period tracking apps are free because they make money from your data. That data gets sold to advertisers, shared with data brokers, and in some US states has been requested by law enforcement. We found this unacceptable. So we built Clio Daye.

Everything you track in Clio Daye lives only on your device. There is no account to create, no server receiving your data, no cloud backup, no subscription, no ads. We have no access to your data. Nobody does except you.

That was the whole reason we built this.

How it works

Clio Daye covers the things that matter in day-to-day cycle tracking. You can log flow intensity, 15 different symptoms, mood, and notes. It shows your current cycle phase and predicts when your next period is likely to start, with an honest uncertainty range rather than a false-precision date. Over time, it surfaces patterns in your flow, symptoms, and mood so you can see what your own cycle actually looks like.

Most apps tell you when your next period is due. Clio Daye shows you a rolling six-month picture of your cycle so you can plan ahead, not just react. Useful for travel, events, or simply knowing what kind of week you're heading into.

Everything is protected by Face ID, Touch ID, or a PIN. If someone else picks up your phone, they cannot open the app without your permission.

Who it's for

Anyone who has a menstrual cycle. Clio Daye uses body-neutral language and doesn't assume gender. It's designed for people across all life stages, from first cycles through perimenopause.

A lot of people who try Clio Daye have already had a bad experience with another app. Maybe you found out your previous app shared your data in ways you never agreed to. We built this for exactly that reason.

Open source and free, forever

Clio Daye is free with no subscription, no premium tier, and no advertising. The source code is public at github.com/pjaol/safeflow so anyone can read it and verify the privacy claims for themselves. We're not a venture-backed startup optimizing for growth. We're a small team who thought this tool should exist and built it.

A note on what this isn't

Clio Daye is not a contraceptive tool and should not be used as one. Predictions are estimates based on your logged history and become more accurate as you log more cycles. If you need contraception or have medical concerns about your cycle, please talk to a healthcare provider.

Requires iOS 17.5 or later.