Questions, answered

Twilune is a private period tracker and mood app. It predicts your period and cycle phases from your own history, shows how today might feel in your phase, and has calm tools for the hard days. There is no account, and your logs stay on your phone.

Yes. Tracking, predictions, the calendar, the daily forecast, SOS and the core calm tools are free for good, with no ads. Premium is optional and adds pattern insights, unlimited chats with Siderelle, the full calm-skills library and more.

Twilune is in closed testing on Google Play for Android. You can also use it in your browser on any phone, including iPhone, and add it to your home screen. See how to get Twilune.

Anyone aged 16 and over who has periods and wants to understand how their cycle shapes their days. Intimacy content is only shown to adults.

Only on your phone, in the app's private storage. On Android 9 and newer it can also ride along in your phone's own end-to-end encrypted Google backup, if you have that switched on, so a reinstall brings it back. We never see it. You can export a backup file or delete everything at any time from the Me tab.

No. There is no sign-up, no email and no phone number. You open the app and start.

No. There are no ads and no advertising or tracking SDKs, and we never receive your logs, so there is nothing to sell. If you say yes, the app sends pseudonymous usage counts (which screens and tools get used, never what or when you log) to PostHog in the EU. It is off unless you turn it on. Details are in the privacy policy.

Yes. You can set a PIN so nobody who picks up your phone can open your logs. Reminder texts on your lock screen never mention your cycle, body or health.

In the app, go to Me and choose Delete all my data. It takes two taps and removes everything from your phone. See delete your data for the details, including purchase records.

Siderelle answers on your phone. If an online version is ever switched on, you are asked first, and only your recent Siderelle messages and a small cycle context (phase, cycle day, days until your period, whether it is late) are sent, never your logs or journal. Messages about self-harm stay on your phone.

From your own logged history. It shows the next period as a range with a confidence level instead of a single made-up day, and it gets better as you log more cycles. Read why predictions are ranges.

No. Predictions are estimates for planning and understanding your body. Twilune is not a medical device or a birth-control method and never shows "safe days".

Twilune still works. The predicted range is wider when your cycles vary more, and when your period is late, it says so plainly instead of quietly moving the date. If a light bleed comes, it asks whether that was your period. If your cycles change a lot or stop, talk to a doctor.

A friendly name for the four cycle phases: inner winter (your period), inner spring (follicular), inner summer (around ovulation) and inner autumn (luteal). Each day, Twilune shows what energy, mood and focus often look like in your season. Try the cycle phase calculator.

Guided breathing (physiological sigh, box breathing, 4-7-8 and a cramp-ease belly breath), 5-4-3-2-1 grounding, a mood check-in and an SOS screen that keeps crisis lines on screen. Read about which breath to use when.

Lumi is a small companion that grows as you look after yourself, and never wilts when you miss a day. Siderelle is a calm guide you can ask why you feel the way you do. Siderelle knows where you are in your cycle and offers general wellbeing information, not medical advice.

Yes, if you want to. You send a private link with only the details you pick, plus phase-by-phase tips for supporting you. You can also make a story card of your season. See how partners can help during PMS.

€6.99 a month, €39.99 a year or €89.99 once for lifetime, through Google Play. Prices in other currencies are set by Google Play. See what Premium adds.

Nothing is charged. The 7-day trial needs no card. When it ends, Premium features lock again and you can choose a plan if you want one. Your data and the free features stay exactly as they were.

No. Twilune is a self-care app. It does not diagnose, treat or prevent any condition. If your periods are very painful or heavy, stop, or your moods make life hard, please talk to a doctor.

Call your local emergency number now (112 in Europe, 911 in the US and Canada). In the app, the SOS screen keeps crisis lines on screen. In the US you can also call or text 988.