Safe to use · Simple to love · Yours for life

A period app that stays yours.

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.

iOS · Android 14 languages Phone and tablet
Today

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

Pay $4.99 once, and never pay again. 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. 

How it works

Four simple tabs. Everything right where you need it.

Cycle0 opens on Today, every time. Move a slider or two, tap a chip if something is worth noting, and you are done — no screens to work through, nothing to confirm. The other three tabs are there for when you feel like looking back.

Today
Today Log the day and stay where you are — the button turns to “Saved”.
Cycle
Cycle Where you are now, in words rather than a verdict.
Calendar
Calendar The month at a glance, and where you fix a day you missed.
Trends
Trends Your own history, with nothing read into it.
The choice most apps make for you

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.

Standard tracking On from the first launch Advanced capturing Five advanced tools — completely optional, off by default.
Every day Bleeding, mood and wellbeing sliders The same three sliders, plus one card below them
Symptoms Chips you can hide, reorder or write yourself Unchanged — your chips stay your chips
Pain A chip, if you added one 6-step scale based on daily impact, location, and pain quality
Where it hurt Location chips with a visual body map
Also records Bowel, bladder, how the day went, medication taken
Time to log a day About ten seconds Under a minute
In the report Cycle averages, daily entries, and notes Adds dedicated pain pages and a visual recurring map
Today, with the pain card open

Descriptive words, not arbitrary numbers.

When asked about pain, "a 7 out of 10" tells very little. Cycle0 anchors its pain scale to real-life impact—like “Stopped me working”—so you can share clear, meaningful context with whoever is caring for you. It never asks you to name a condition; each tool simply notes down what happened, nothing more.

Questions about the deeper tools →
The report

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.

  • · Designed for quick reading: Summarises cycle lengths, bleeding days, and symptom patterns right at the top, so a healthcare provider gets the big picture in seconds.
  • · 100% private, generated on-device: Your PDF is created entirely on your phone. No servers, no uploads — it stays a local file until you choose to print or share it.
  • · Complete daily history: Includes your exact daily entries, notes, and optional pain-location maps, so you have a factual record ready for your appointment.
Report, page three
Report, page two
Report, page one
A lifetime, not a season

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.

1

Starting out

Irregular cycles are completely normal at first. Cycle0 never forces a fake prediction date just to look smart.

2

Settled

Once your body finds a rhythm, Cycle0 can give you a calm, expected date for your next period.

3

Changing pace

If your cycle starts drifting, the app stays quiet and simply counts the days rather than guessing.

4

Menopause

Transition whenever you are ready — one tap switches the app to count months instead of cycles.

5

After

Clean, clear support without scary colours or alarmist warnings.

The Cycle tab with too little history to name a date
Too little history to name a date
The Cycle tab after a long gap, counting the days instead of guessing
A long gap: days since, and what it does know
The Record tab after periods have stopped, counting months
Record, counting months
Where your entries go

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.

Backup

To storage you already own

An encrypted backup file, to your own cloud or your own disk. It is the only thing that can be brought back in.

Report

PDF or CSV

A report is something to read. It goes out, it does not come back.

Never

Everything else

Delete everything, from inside the app, without asking anyone.

Read the whole privacy position →

The awkward one

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.

Instead, it is $4.99 once, up front. 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.

One purchase, for as long as you have cycles

Around $4.99 on your store. Prices differ by country and the store shows yours before you buy.

Prices in local currency may vary with store rounding and VAT.