One vault, one key, or your own door
Apple Health opens with your phone. Whoever knows your passcode, or can hold the phone up to your face, is inside it: every period you have logged, the fertile-window calendar, and everything else Health holds, steps, sleep, medications, mental health. Since iOS 18 you can put Face ID in front of the app, and that helps against a glance, but the passcode still opens it and the lock is the phone's, not Health's. Apple Health is one shared vault behind one shared key.
KeepCycle has its own PIN. It is not your phone passcode, you can make it different, biometric unlock is optional and off until you turn it on, and the app locks again the moment you leave it. Knowing the phone's passcode gets someone to a keypad, and no further. The app also holds nothing but your cycle, so there is nothing else behind that door to lose.
This matters in plain, practical terms. Period data can carry real legal exposure in US states that restrict abortion: private digital records have already been obtained by warrant and used to prosecute an abortion in Nebraska, and it matters at any border crossing, in any relationship where a phone gets picked up, and in any home where a passcode is shared. This is not a promise we are asking you to trust. It is how the app is built, and it holds even if we wanted it not to.
And it cannot pretend to be anything else
Apple Health says Health on the home screen, under the white icon with the red heart. It cannot be renamed, cannot be given a different icon, and, because it comes with iOS, it is one of the apps iOS will not let you hide. Inside it, the section is called Cycle Tracking and the timeline shows red circles for period days and a blue oval for the fertile window. A locked app keeps its contents out of notification previews and search, and you can move it off the Home Screen into the App Library; what you cannot do is make it look like anything other than what it is.
KeepCycle's Stealth Mode turns the whole app into a plain journal under a name you choose, on the home screen, on the lock screen, in reminders, and in the app switcher. The icon can be a notes app, a calculator, a weather app. Someone scrolling your phone sees a journal.
| KeepCycle | Apple Health Cycle Tracking | |
|---|---|---|
| What opens it | Its own PIN, free. Not your phone passcode; biometric unlock is optional and off by default; it re-locks the moment you leave. | Your phone. On iOS 18 or later you can also require Face ID or Touch ID, but the phone passcode still opens it, and the lock covers all of Health, not just Cycle Tracking. |
| Can it be disguised? | Yes, Pro. Stealth Mode gives it a neutral name everywhere and a choice of discreet icons. Nothing on the screen says what it tracks. | No. It is the Health app, with the Health icon, and iOS does not allow apps that ship with it to be hidden. It can be moved to the App Library. |
| What sits next to your cycle data | Nothing. KeepCycle holds only what you type into it. | Everything else in Health: activity, sleep, medications, mental health, medical records if you have added them. One app, one door. |
| Where the data lives | Only on your phone. There is no KeepCycle server and no account, so there is no copy anywhere else. | On your phone, and in iCloud if Health syncing is on. With two-factor authentication that copy is end-to-end encrypted. |
| Who else can read it | No one. There is no interface for other apps to read KeepCycle's data. Sharing is a file you make on purpose, containing only what you tick. | Any app you grant Health access to, and anyone you invite through Health Sharing. Both are under your control and both are off until you turn them on. |
| Fertility content you did not ask for | Fertile-window estimates appear only if your goal is set to trying to conceive. Every other setting shows none of it. | Fertile Window Estimates and fertility notifications are options you can turn off. Period predictions can be hidden too. |
| Period, flow and symptom logging | Yes, free. Any past day can be edited or deleted. | Yes, free. Period days, flow level, spotting, a long symptom list, and edits to past days. |
| BBT, cervical mucus, ovulation tests | Yes, Pro | Yes, free, once enabled under Options. |
| Ovulation estimate from wrist temperature | No | Yes, with Apple Watch Series 8 or later or Apple Watch Ultra. This is something only Apple can do. |
| Perimenopause | Yes, Pro. A mode that tracks gaps and symptoms instead of a 28-day cycle. | No dedicated mode. Hot flashes and night sweats are in the symptom list, and Cycle Deviation notifications flag irregular, infrequent or prolonged periods. |
| Bring your history with you | Yes, free. KeepCycle imports your Cycle Tracking history from Health on your phone: read once, never written back. | Not applicable. |
| Summary for an appointment | Yes, Pro. A PDF made on your phone. | Yes, free. Export PDF of the last 12 months, or of a single cycle. |
| Medication reminders | Yes, Pro. Scheduled by your phone. | Yes, free, through Health's Medications feature. |
| New phone, lost phone | Only if you kept an encrypted backup file (Pro). Otherwise the history is gone with the phone. That is the cost of having no server. | Restores from iCloud if Health syncing was on. |
| Price | Free, with one small non-personalized banner on the lock screen. Pro is $1.99 a month and has no ads. | Free, no ads, no paid tier. |
The honest summary
On privacy from the company, Apple Health is strong. The iCloud copy is end-to-end encrypted and there is no advertising. If your only worry is a business on the other end, the built-in app already handles it well, and we are not going to pretend otherwise.
KeepCycle is for the other worry: the person on your side of the phone, or anyone who can make you unlock it. Apple Health opens with the phone and cannot look like anything but Apple Health, with everything you have ever logged about your body behind one door with your step count. KeepCycle has a door of its own, can look like a notes app, and holds nothing but your cycle. Switching costs nothing, because it reads your existing history straight out of Health.
What we are not claiming
Apple is not selling your cycle data. With two-factor authentication, Health data in iCloud is end-to-end encrypted. We are not suggesting otherwise; our point is about who can open the phone, not about Apple.
Cycle Tracking is not thin. It logs periods, flow, spotting, a long symptom list, basal temperature, ovulation tests and cervical mucus, predicts periods and fertile windows, flags cycle deviations, exports a PDF, and with a recent Apple Watch estimates ovulation from wrist temperature. Most of that is free, and some of it we cannot match.
iOS 18 made Health lockable. If a Face ID lock on the whole app is enough for you, that option exists and it is free. Our claim is narrower and holds anyway: the phone passcode opens that lock, it covers all of Health at once, and Health cannot be disguised or hidden.
We have not audited Apple's code. Everything above comes from Apple's own support pages, linked below.
The one thing to try first
Install KeepCycle, set a PIN, and take the offer to import from Apple Health. Then open Settings and turn on Stealth Mode. Hand your phone to someone and see what they see.
Sources
- Apple Support, Track your period with Cycle Tracking (logging, factors, predictions, notifications, PDF export, wrist temperature)
- iPhone User Guide, Log menstrual cycle information in Health (what can be logged, Options, and the "About your health data and privacy" paragraph on iCloud end-to-end encryption)
- iPhone User Guide, View menstrual cycle predictions and history (turning predictions and notifications off, Cycle Deviation notifications, Export PDF)
- Apple Personal Safety User Guide, Lock or hide apps on your iPhone ("Apps that come installed with iOS 18 or later can't be hidden"; what a locked app hides)
- Apple Support, Delete built-in Apple apps (Health can be deleted, which turns Cycle Tracking off; the data stays on the phone)
- NPR, Nebraska police used Facebook messages to investigate an alleged illegal abortion (August 2022) (private digital records obtained by warrant and used in an abortion prosecution)