Period tracker · mood forecast · calm tools

Finally, a period app that gets your moods.

Twilune predicts your period, shows how today might feel in your phase, and helps you calm down in two minutes when it all gets too much.

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Free. No account. On Android, or in any phone's browser.

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Twilune's Today screen: cycle day 22, about 7 days until the next period shown as a range, luteal phase, and a forecast card that reads Nesting instincts

€0Core features free for good. No ads.
0 accountsNo email or number. Logs stay on your phone.
2 minGuided breathing and grounding, when it's too much.
18–90 daysIrregular, PCOS and perimenopause cycles count.

How it works

Three things, done properly.

Twilune's calendar with logged period days and the predicted next period shown as a range — **Predictions that stay honest**Your next period and phases, learned from your own history and shown as a range with a confidence level. Late? It says so instead of quietly moving the date.

Twilune's patterns screen showing which moods and symptoms tend to appear in each phase — **Your moods, explained**A daily forecast of energy, mood and focus for your phase, and after a couple of cycles, your own patterns: which feelings tend to show up when.

Twilune's Breathe screen guiding a physiological sigh, with box breathing, 4-7-8 and a cramp-ease belly breath to choose from — **Calm in two minutes**Guided breathing, 5-4-3-2-1 grounding, a mood check-in and an SOS screen that keeps crisis lines in reach for the hardest moments.

Your inner seasons

You're not "too much". You're cyclical.

Twilune gives each phase a season, so a rough day makes sense instead of feeling like it's you.

Inner winterRest, warmth, fewer plansMenstrual phase

Inner springFresh energy, new ideasFollicular phase

Inner summerSocial, bold, outgoingAround ovulation

Inner autumnNesting, boundaries, softnessLuteal phase

These are common patterns, not rules. Your own logs show what your seasons are really like. Which season are you in today?

Every kind of cycle

Built for the cycle you actually have.

Not every body runs on 28 days, and not every bleed is a period. Tell Twilune what is true for you and it only shows what it can honestly know.

On the pill

Pill, ring or patch with a break? Twilune predicts your pill bleed and drops ovulation and fertile days, because your method stops them. On a hormonal IUD, implant or a pill with no break, it simply keeps your log. A discreet daily pill reminder is built in.

Irregular or PCOS

Cycles from 18 to 90 days count as real data, and the forecast widens honestly instead of pretending. Fertile days are only shown when your cycles are steady enough to place them.

Perimenopause

Long gaps and changing bleeds are expected, not errors. Late periods get calm wording and a gentle nudge to check in with a doctor, never alarm.

Also inside

Gentle company, never pressure.

Lumi grows with you

A small companion that grows as you look after yourself. Miss a day? Lumi never wilts. No guilt, ever.

Ask Siderelle

A calm guide who knows where you are in your cycle. Ask why you feel the way you do, or talk through a hard day. General wellbeing information, not medical advice.

Share only what you choose

Send a partner a private link with just the details you pick, plus phase-by-phase tips for supporting you. Or make a story card of your season.

Private by design

Your cycle is nobody's business model.

Period apps have faced regulators over sharing health data. Twilune was built so it can't: no account is needed and no Twilune server holds your logs (an optional backup goes to your own Google Drive, not to us). What to check in any period app.

No account needed: no email or phone number to start
Cycle, moods and journal stored only on your phone
No ads and no tracking SDKs; usage counts only if you say yes
PIN lock for shared phones
Optional backup to a hidden folder in your own Google Drive
Export a backup, or delete everything in two taps

Fair pricing

Free where it matters.

Free

€0

Period and phase predictions, with honest ranges
A birth-control mode and a daily pill reminder
Calendar, symptom and mood logging
Daily forecast for your inner season
SOS, breathing, grounding and core calm tools
Lumi, story cards and the partner link

Premium

€39.99 a year

Your personal patterns by phase
Unlimited chats with Siderelle
The full calm-skills library and every journal prompt
Partner mood sharing
7-day trial with no card and no automatic charge

Also €6.99 a month or €89.99 once. What Premium adds

From the blog

Understand your cycle, kindly.

Cycle and phases

Why period predictions are ranges, not datesCycle length varies from month to month, even in regular cycles. Why period predictions work best as a range, and when irregular periods need a doctor.

PMS and moods

PMS or PMDD? How to tell the differencePMS and PMDD share symptoms, but PMDD is more severe and disrupts daily life. Learn the signs, how it is assessed, and what to bring to a doctor.

PMS and moods

PMS mood swings: what actually helpsWhat can help PMS irritability, low mood and anxiety: exercise, sleep, CBT-style skills, tracking, and when to talk to a doctor. Evidence sorted by strength.

All articles

FAQ

Questions, answered.

What is Twilune?

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. No account is needed, and your logs stay on your phone unless you turn on backup to your own Google Drive.

Is Twilune free?

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.

Where is my data stored?

On your phone, in the app's private storage. If you turn on Google Drive backup, a copy also goes straight from your phone to a hidden folder in your own Google Drive, so a new phone can restore it; it never passes through us. 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.

Does Twilune sell or share my data?

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.

Can I use Twilune as contraception?

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".

Does Twilune work if I'm on the pill?

Yes. Tell Twilune when you set up, or later in Me. On a pill, ring or patch with a monthly break, it predicts your pill bleed. On a pill with no break, a hormonal IUD, an implant or the shot, it keeps your log without a forecast. In both cases it hides ovulation and fertile days, because your method stops ovulation, and you can turn on a discreet daily pill reminder. A copper IUD keeps a natural cycle, so choose "No" for that.

What happens when the free trial ends?

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.

Meet your inner seasons.

Predictions you can trust, a forecast for how today might feel, and calm in two minutes. Free, with no account needed.

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About 8 MB on Android 7 and newer. On iPhone, add it to your home screen from Safari.

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