The tilde means estimated.
You can tell at a glance when the day is approximate.
Understand her cycle.Show up better.
Log an exact date. Or simply “on her period now” or “PMS signs.” Cycles turns it into a clear best guess, shows how confident it is, and gets more useful as context builds.
- No account
- On-device only
- Free for early users
Lea’s cycleDrag to explore
Medium confidence±3 days
Based on premenstrual signs noted 11 days ago.
You probably do not know every date.
That is the point.Cycles works with honest signals instead of asking you to invent precision.Works with what you know
You do not need the exact date to begin.
Pick the information you actually have. Cycles decides how much to trust it and says so plainly.
What Cycles does
A useful range, not a made-up date.
Cycles places the likely start within the period window, then keeps the uncertainty visible.
Medium confidence±2 days
Confidence fades honestly as information gets older
Honest uncertainty
A best guess should look like one.
Cycles never hides the difference between an exact date and an estimate. Three small signals keep the uncertainty readable.
The range stays visible.
Soft signals and irregular cycles widen the window.
The basis is written out.
No mystery score—just the information behind the guess.
The cycle, in context
Four phases. Written for the person paying attention.
The app personalizes the ranges. This 28-day example shows the kind of support that may land well.
Menstrual
Days 1–5Energy is often at its lowest—cramps and fatigue are common.
Low-key plans and warmth go a long way.Follicular
Days ~6–11Energy, mood, and focus often climb day by day.
The best stretch for plans and new things.Ovulation window
Days ~12–15Energy and confidence often peak around these days.
Shown as an estimate, never contraception advice.Luteal
Days ~16–28The final days can bring PMS—mood dips, cravings, tiredness.
Don’t take it personally. Patience and snacks.Every body is different—Cycles learns each person’s real rhythm from whatever you log.
Yours alone
The data stays with you.
Cycle information is sensitive, so Cycles keeps the architecture deliberately small: one iPhone, no account, no analytics.
No account or cloud
Profile and cycle data stays in local app storage.
Optional Face ID
Lock the app when it returns from the background.
Deliberate export
Create a portable copy only when you choose.
Real deletion
Remove one profile or wipe everything from the device.
On-device onlyNo Cycles account
Questions, answered
The clear version.
If the app is making a guess, it should be direct about how and why.
You can log that her period is happening now, note PMS or premenstrual signs, or add a plain note. Cycles weighs each signal differently and shows how uncertain the resulting estimate is.
That depends on what has been logged and how recent it is. An exact period start produces a tighter estimate; softer or older information produces a wider range. Cycles always shows its confidence and basis instead of pretending every date is exact.
Yes. Only add information someone has chosen to share with you. Cycles is designed for awareness and support, not monitoring, and any profile can be deleted at any time.
Profile and cycle data stays on your iPhone. Cycles has no account, cloud sync, or analytics. You can optionally use Face ID, export a copy, or delete everything from the device.
The full app will be free for early users. If pricing ever changes for new downloads, anyone who already has Cycles for free will keep it free. A subscription is not planned.
Cycles is coming soon to the App Store for iPhone. There is no live store listing yet, so the buttons on this page stay in a coming-soon state.
Coming soon for iPhone
Stay tuned in, without pretending to know everything.
The full app will be free for early users—and stay free for them if pricing ever changes later. A subscription is not planned.
Free for early users · iPhone