One tap logs your period. The people you choose finally know what is coming, instead of guessing.
Log a period in one tap, and five symptoms if you want them. Predictions come from your own cycles and arrive with an honest range, never a single confident date. Invite a partner or a family member to see exactly what you choose, on a page that needs no app and no account, and stop it whenever you like.
The tracking is fine. Everything around it is the trouble.
Logging a period was solved years ago. What did not get solved is how much setup stands in front of it, how confident the predictions pretend to be, and the fact that the person who wants to help has no idea what week it is.
Composite complaints about tracking apps in general, not quotes from a named person: there is no App Store history to quote yet.
Log, predict, share, and the share is the reason the app exists
There is no onboarding wizard to survive. The app opens on the button.
Log
One tap starts a period, one ends it. Five symptoms are there if you want them. Nothing else asks for your attention, and your Apple Health history is read in so it is useful from the first day.
Predict
After three logged cycles the prediction comes from your pattern rather than an average. It always arrives with a plus-or-minus, never a single date dressed up as certainty, and before those three cycles it says plainly that it is using a typical 28 days.
Share, precisely
Invite one person by link. Choose what that person sees. Change it, or end it, whenever you like. They need no app and no account, and nothing about your cycle leaves your phone until you do this.
Sharing is the point, not an afterthought
Most tracking apps stop at the person doing the tracking. Fortuity Cycle is built for the people around you too, so the ones who want to help actually know what is happening.
You invite someone by link
A partner, a mother, a sister, a close friend. They open a web page. No app, no account, no sign-up on their end.
You pick what they see
Phase only, or phase and symptoms too. Each person you invite can have their own view, and you can change it whenever you want.
You can stop any of it instantly
One tap ends a person's access. Nothing stays visible through that link, and nothing shows again until you reopen it.
The moments this is actually for
Your cycle lands on ordinary plans, routines, and relationships. The Support Loop lets you share the context you choose with specific people, by sending one link, without handing over your phone or explaining the same thing twice.
When goodwill needs a map
Your partner wants to help with dinner, take on the heavier chores, or give you more space, but good intentions still leave room for guesswork. You can share a link that shows the part of your cycle you chose to show. When they check it, they have context for the day without trying to read your mood or asking you to explain how you feel. The link does not tell them what to do or make assumptions about your body. It gives them the view you chose, and the two of you decide what to do with it.
Packing bags around the calendar
You are planning a four-day beach weekend and the dates matter. Instead of comparing calendars again, your travel companion can open the link you shared and see the cycle-date estimate you chose to include. The estimate is shown as a range, never as a promise and never as a recommendation about what to plan. It is one piece of information you use together when deciding between the cabin, the mountain hike, and a looser weekend.
Checking in across time zones
Your sister lives two time zones away and you want an easier way to stay close during busy weeks. She does not need your full log. You can give her a phase-only view, keeping symptoms and everything else out of what she sees. She opens her link when she wants context before calling or leaving a voice note. Nothing is sent to her. She checks the page herself, and you decide what is on it.
Skipping the well-meant question
A close friend notices when you order tea instead of espresso or pass on a late night out. Sometimes the question is welcome. Sometimes you would rather enjoy the afternoon without discussing your body. A phase-only view gives her the context you decided to share, without opening the rest of your record. She can check the link instead of asking, and you can change or end her access without changing what anyone else sees.
Logging at 11pm, in bed
It is 11pm, the lights are off and you are already under the covers when your period starts. You do not want a long survey, a 10-point mood scale, or questions about unrelated habits. Open the app, tap once to mark the start, and close it. The next tap, whenever it comes, marks the end.
Closing the window right now
Relationships and boundaries change. If someone should no longer see your cycle information, open your sharing list and revoke that person's link. Access ends immediately, and only for that person. Opened 10 seconds later, that link returns exactly the same not-found response the server gives for an address that never existed. No denial notice, no alert, no email, no text. A revoked link cannot be told apart from one that was never real.
Restraint is the feature
Many trackers open with screen after screen of setup before you can log anything real. Fortuity Cycle opens on the one button that matters.
One tap starts a period
That is the entire log. Five symptoms are there if you want them, and nothing else competes for your attention.
Predictions from your own data
Once you have logged three cycles, predictions come from your pattern. Before that, the app uses a typical 28-day cycle and says so plainly.
An honest range, not a false date
Every prediction comes with a plus-or-minus, such as give or take two days, instead of one date presented as certain.
Works with your Apple Health history
It reads what is already there so it is useful from day one, and writes back so your record stays yours if you ever leave.
Built so your data stays yours
Cycle data is intimate. These commitments are built into the product's engineering, and enforced by it.
The record stays yours
Your cycle record belongs to you, it lives in Apple Health, and the estimates say out loud how confident they are.
Fortuity Cycle is on iPhone, by invitation. There is no App Store listing and no Android app. It connects to Apple Health in both directions: it reads the cycle history already stored there, so the app is useful on your first day rather than after three months, and it writes new entries back, so the record stays in your own health store even if you stop using this app.
Cycle-date estimates come from your own logged patterns once three cycles are recorded. Before that, the app uses a typical 28-day cycle and says so on screen, rather than implying a personalisation it does not have yet.
A range, never a bare date
Every estimate is published with a plus-or-minus, because that is what the math actually supports. The engine is checked against answers derived by hand, and a mutation script breaks it on purpose and requires the suite to go red, so the tests would catch a real bug rather than passing regardless.
Only what you chose to log
No mood scales, no habit surveys, no fields you did not tap yourself. What lands in Apple Health is exactly as sparse or as detailed as you made it, deliberately, so the record reflects your choices rather than a form the app made you fill out.
Fertility output is off by default
Fertility and ovulation estimates stay off unless you turn them on. Fortuity Cycle is not a Food and Drug Administration (FDA)-cleared device, it is not contraception, and it does not give medical advice. Nothing here is for diagnosing a condition, making a medical decision, or preventing pregnancy.
A deliberately narrow product
No pregnancy mode, no conception coaching, no community, no content library, no AI chat. This product stays narrow on purpose, rather than filling out a backlog: the larger apps are genuinely better at breadth, and this one is not competing there.
Nothing is charged and no price is published. Access is by invitation, said plainly. What the product does is narrow on purpose: record your cycle, keep it in Apple Health where it is yours, and share only the view you chose with the people you picked.
Against Flo and Clue, honestly
Both are far bigger than this, both are good, and both already let you share with a partner, so that is not the claim. The claim is how the sharing works. Every figure below was read off that company's own pages on 26 July 2026.
| Fortuity Cycle | Flo | Clue | |
|---|---|---|---|
| Sharing with someone else | A link per person, and you choose what each one sees | Yes: Flo for Partners | Yes: partner sharing |
| What the other person needs | A web page. No app, no account, no sign-up | The partner installs the app | Not described as app-free |
| Ending someone's access | One tap, immediately, per person | Not described | Not described |
| Where your cycle lives by default | On your phone. It reaches a server only once you invite someone | In the account, with Anonymous Mode offered as a separate feature | In the account, under European Union (EU) data-protection law |
| How a prediction is stated | Always with a plus-or-minus, never one confident date | Predicted dates | Predicted dates |
| People already using it they win | A new app in invite-only TestFlight | "Over 420 million people", in their own words | "Trusted by millions in over 190 countries" |
| In the App Store and on Android they win | Neither. Invite-only TestFlight on iPhone only | Both stores | Both stores |
| Breadth they win, and we are not trying to | A log, a prediction, and sharing. No pregnancy mode, no conceiving coaching, no community, no content library, no AI chat | Pregnancy, conceiving, perimenopause, a symptom checker, a health library, secret chats, a medical team of 100+ | Conceiving, pregnancy, perimenopause, an encyclopedia, research partnerships with Oxford, Berkeley, and the Massachusetts Institute of Technology (MIT) |
| Legal home for your data Clue wins | United States | Not described | EU-based, and they state your data is protected by EU privacy law wherever you are |
| What it costs | Nothing today, and no price is published | Free tier plus Flo Premium. Their own page says the price lives in their Help Center rather than on the site | Free tier plus Clue Plus. No price published on the site either |
Scroll the table sideways to see every column.
Sources. Read on 26 July 2026 from flo.health, flo.health/flo-premium and helloclue.com. "Not described" means the capability is absent from their own published pages, not that we tested it and it failed. Neither company publishes a subscription price on its website, which is why no number appears in their columns rather than a guessed one. Check the linked pages before deciding anything on this table.
Nothing is charged, and no price is published
That is the honest state rather than a tactic. There is no card to enter, no trial counting down, and nothing to cancel.
- The whole tracker: logging, symptoms, predictions with their range
- Apple Health read and write, so the record stays yours
- The Support Loop: invite, choose the view, end it whenever
When a price exists it will be posted on this page before a single charge happens: no sales call, no card sitting on file, and no renewal you have to discover. If you see a price for this app anywhere else, it is not ours.
Straight answers
Can I get it today?
On iPhone, in invite-only TestFlight. There is no App Store listing yet and no Android app. Leave an address and you will be told when that changes.
Does my cycle really stay on my phone?
Until you invite someone, yes. The service has no endpoint that takes a general upload of your log; what reaches a server is the share surface you deliberately create. End a share and that access ends with it.
What exactly does the person I invite see?
What you chose for them, and nothing else: phase only, or phase and symptoms. Each person you invite has their own view. A share link resolves to one person's surface and never to an account, and that boundary is held by a test that renders your surface while a decoy exists and asserts not one decoy value appears, with a positive control so a page that renders nothing cannot pass by doing nothing.
Does it tell me when I am fertile?
Not by default, on purpose. This is not an FDA-cleared device and it is not in the contraception lane. It describes what your own data shows and never prescribes.
Does anyone get notified automatically?
Not today. Delivery is switched off in the service, so the app previews what a notification would say rather than sending one. Turning any real delivery on is a separate decision that has not been made.
Is my data sold, or used for ads?
No. Cycle data never touches an advertising network or a third-party analytics tool, and it is never sold or brokered. Analytics inside the app is a closed list of feature names, never content. This marketing page measures visits with privacy-first analytics, and only after you accept the banner.
How is this different from Flo or Clue?
Both are enormously bigger and both already offer partner sharing, so that is not the difference. The difference is that sharing here is per person, revocable in a tap, needs no app on their end, and is the only reason anything leaves your phone. The full comparison, including the rows they win.
What if I stop using it?
It writes back to Apple Health, so your record stays in the place you already keep your health history rather than only inside this app.
What it does not do
Some of this is not built yet. Some of it is a decision.
- Invite-only TestFlight, and nothing else. No App Store listing, no Android app.
- No automatic notifications yet. Delivery is off in the service; the app previews what would arrive.
- Fertility and ovulation output is off by default, deliberately. Not an FDA-cleared device, and not a contraception tool.
- No pregnancy mode, no conceiving coaching, no community, no content library, no AI chat. That is the product's shape rather than a backlog.
- Five symptoms, not 50. If you want an exhaustive symptom taxonomy, the bigger apps are genuinely better at it.
- It describes and never prescribes. It is not medical advice, and anything about your health is a conversation with a clinician.
Track it in seconds. Share it on your terms.
Fortuity Cycle keeps the logging small and the sharing precise, so the people around you can help with what is actually happening.
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