MoonstrateComing soon
to iPhone and Android
A period tracker that keeps your cycle to yourself.
Log how you feel and what you tried, and let your own data show you what works. Yours, never ours.
Learn your cycle. Live in season with it.
Your four inner seasons
Your cycle moves through seasons, and so do you. Each phase gets food, movement, and self-care that fit how you actually feel. Suggestions, never prescriptions.
Insights from your own logs
Track what you tried and how it went. Over time the app shows what works for you and what doesn't. Your patterns, never a forecast.
How Insights worksLearn how cycles work
A plain-language, graded guide to the science: what's solid, what's a maybe, and what we refuse to sell you.
Start readingPrivacy you can check
No account, no ads, no trackers. Your data is encrypted on your phone and backed up only to your own cloud. And because the whole app is open source, you don't have to take our word for any of it.
Learn your body's rhythm from your own logs
Each day you can log how you feel and what you tried: sleep, food, movement, rest, anything you want to test. Over time, Insights shows you which of those went with better days and which didn't, drawn only from what you logged. That is how you learn your body's rhythm, the stretches where you tend to have energy and the ones where you don't, and what actually helps when a rough patch lands.
Insights describe your patterns. They never forecast, and they never hand down rules. When there isn't enough logged yet to say something honest, the app says nothing rather than guessing.
When a cycle runs long, short, or heavier than usual, the Learn tab explains what can shift a cycle, like stress, illness, travel, poor sleep, or some medications, so you can put your own entry in context and know when a change is worth a conversation with a clinician.
What we won't do
We won't hand you a meal plan or a workout that promises to "unlock" your hormones. The evidence for timing food and exercise to your cycle phases is thin, and a lot of what gets sold as science is closer to marketing. The changes in your body across a cycle are real; the strict rules built on top of them mostly aren't. So we'll show you what's actually known, keep the seasons as a way to notice your own patterns, and leave the rulebook out of it. What you log about yourself will tell you more than any universal chart.
The promises in one breath
- Always free
- No ads
- No trackers
- No account. Ever.
- Only on your phone or your own cloud
- Open source under AGPL-3.0
- Nothing about weight or calories
- For every body that menstruates
- Not medical advice
Inside the app
- A daily check-in for mood, energy, symptoms, and what you tried
- Insights from your own logs: what works for you and what doesn't
- Four inner seasons mapped to your cycle, with phase-aware food, movement, and self-care
- The Learn tab: a graded, sourced guide to how cycles work
- Honest next-period prediction, a range, not a date
- A calendar that looks ahead
- Inner Seasons mode or a stripped-back Simple mode, your call
- Three security levels to choose from: Strong, Stronger, Strongest
- Backup to your own cloud, never ours
Predictions that tell the truth
Your next period comes as a range, not a fake-precise date, because bodies aren't clockwork and a wrong "you're due Tuesday" helps no one. The window is tight if your cycles are regular, wider if they vary.
Private by default and open to check
Your data lives on your phone, encrypted. Turn on backup and it goes to your own iCloud or Google Drive, encrypted before it leaves your phone, and it never comes to us. No account. No ads. No trackers. Nothing on our end to leak, sell, or hand over, because we never have it. Choose how much protection you want, from a simple secret (a PIN or passphrase only you know) to a full lockdown, and every level is free. And Moonstrate is open source, so anyone can read the code and confirm we do what we say.
Free. It stays free.
Everything in Moonstrate is free for everyone. No premium tier, nothing to unlock. If it helps you, there is a tip jar. Tipping changes nothing about what you get. You never pay to understand your own body.