Cycle0

It takes about ten seconds a day. Three quick sliders, tap what you felt, and you are done. There is nothing to learn, nothing to get wrong, and no confusing health jargon.

Cycle0 handles the maths in the background: how long your cycles run, when to expect the next one, and what symptoms keep coming back. Best of all, there are no accounts, no sign-ups and no passwords to remember. Everything you write stays strictly on your device — where it belongs.

Nobody reads it but you
There is no account and no sign-up, so there is nothing about you for anyone to find. What you write down stays on your device. If you want a safety copy it goes to your own iCloud or Google Drive — never to us, because there is no us to send it to.

One price, once
No monthly fees, no subscriptions, and no features quietly locked behind a paywall. You get the full app from day one — including every report and advanced tracking tool.

No spam. No unwanted advice.
Cycle0 only speaks up when you ask it to. You can set quiet, local reminders for your likely start dates or daily logging — and that is it. It will never flood your phone with random wellness tips, try to diagnose you, or push unwanted medical advice.

Four simple tabs. Everything right where you need it.
• Today — Log the day and stay where you are — the button turns to “Saved”.
• Cycle — Where you are now, in words rather than a verdict.
• Calendar — The month at a glance, and where you fix a day you missed.
• Trends — Your own history, with nothing read into it.

Easy for every day. Thorough when you need it.
Most months, you just want to log a quick entry and move on. But if an appointment is coming up and you are tired of trying to remember every detail, deeper tracking tools are ready to turn on — exact pain spots, and what it stopped you from doing that day. When you are sitting with a health professional, you can hand over a clear, printed summary instead of relying on memory.

Something you can put on the desk
Ten minutes with a doctor goes differently when you are not reconstructing eight months from memory. Cycle0 lays out your diary as a clear PDF handout — complete with cycle averages, daily logs, notes, and symptom mapping.

An app that grows with you.
Your body does not stay the same forever, and the app should not pretend to either. Cycle0 adapts as your life changes — no matter your age.

Three ways out, all of them yours
Nothing leaves your device unless you send it yourself. No middleman ever touches your data on the way.

Why you won’t find a free trial here
A trial needs to know who you are and when your trial ends. That means an account and a server — the two things this app exists to avoid. One purchase keeps the arrangement simple.
No subscriptions, no surprise charges, and no hidden features. You get to see every real screen on this website before you buy, and if it ends up not being the right fit, standard store refund policies have your back.