Getting started
From install to your first logged day, on any device your family uses. The example here follows Sam, who is setting lunarlog up for herself — the inviting guide picks the story up from there, in both directions.
Install, or open the browser version
lunarlog runs on iPhone, on Android, and in a browser. The phone apps are the full experience, including the lock screen and the optional health-app connections; the browser version is a real lunarlog too, with its own storage trade-offs, explained on that page.
- On a phone, lunarlog will install from the App Store and Google Play. Neither listing is open yet. In a browser, go to app.lunarlog.app.
- Open the app. On a phone, everything you log is protected by the device's own screen lock from the very first launch — the lock screen appears before the app's contents, and stays between your data and the world every time after.
In a browser the order is the other way round. The browser version keeps nothing on the computer, so there is nothing to set up until you are signed in: create the account or sign in first — with an email and password, Google, or Apple — and then choose Add profile on the page that says No profiles yet. The rest of this guide follows the phone apps.
Set up the first profile
A profile is one person's cycle log — its own name, history, and estimates. Sam's first profile is her own.
- The first screen asks Who is this profile for?. Sam picks Me — the Someone I care for path is the same flow with the minor flag available, for a profile someone else will log for, at least for now.
- Enter the person's name under Name — a first name or nickname is normal; lunarlog never asks for more.
- A few optional questions follow — when the last period started, typical cycle and period lengths — and every one of them can be skipped: A few optional questions to set this profile up — every one can be skipped. The life-stage mode and birth-control answers can be changed later from Edit profile.. Answers sharpen the early estimates; skipping costs nothing.
- Choose the Care mode when it is offered. Standard works for most adults; the life-stage modes change wording and reminders, not what is stored — and the mode can be changed any time from Edit profile.
- Tap Create profile. That is the whole setup — logging takes one tap from here, and the logging guide walks through it.
The account — now or later
You can log for weeks without an account: everything stays on the device. The account is what makes lunarlog more than a private notebook — it syncs a profile across your own devices and carries invitations to the other guardians in the household.
When you are ready, create it from Settings: Create account asks for an Email and a Password, or you can sign in with Google on iPhone and Android, or with Apple on iPhone.
Signing in uploads this device's data only after your explicit consent — the app asks first. From then on, profiles and day entries sync between the household's signed-in devices.
Privacy at a glance
On-device first, account-optional, and protected by the device lock. The full policy lives in Settings.
Entries live on the device under the operating system’s own protection and only appear behind the device lock. Nothing leaves the device until an account is created and sign-in uploads it.
Sharing is always explicit: a profile is visible to exactly the guardians listed on it, each with the role shown there. Nobody else — no advertisers, no data brokers — receives anything.
Crash reports are scrubbed on-device before sending so they never carry health data, notes, dates, or names.
Source: lunarlog app behaviour · Last reviewed
The lock screen
On a phone, the app's contents stay behind the device's screen lock. Reopen lunarlog and you will see lunarlog is locked with a single Unlock step: Everything logged on this device stays protected. Unlock to continue..
If the phone has no screen lock at all, the app says so and offers to open the device settings: lunarlog leans on the protection the operating system already provides, so it asks you to add a passcode, PIN, pattern, or biometric lock rather than invent its own.
Two refinements live in Settings under Privacy & security: an optional in-app PIN on top of the device credential, and Relock after inactivity — how long the app waits before locking itself again when you step away.
Where to go next
- Logging a day — flow, symptoms, tags, and notes.
- Setting up a household — more profiles, and the four guardian roles.
- Inviting someone — bring a parent, partner, or the profile's own subject in.