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Accounts
No sign-up. No email. No password. Open the app and start tracking — Cykel never asks who you are, because it never needs to know.
Period & cycle tracker · Android
Your cycle. Your phone. Nobody else’s.
No accounts. No servers. Your data never leaves your device. Cykel tracks, predicts and explains your cycle entirely on your phone — so a leak of your data isn’t just unlikely, it’s impossible.
Free on Android · Coming soon to iOS
- 0 accounts
- 0 servers
- 0 ads
Meet Cykel
Everything on your phone.
Nothing anywhere else.
0 accounts, 0 servers — nothing to leak
Predictions computed on-device
Works fully offline — even Ask Cykel
Encrypted database, biometric lock
Why Cykel
Nothing to leak.
Nothing to sell. Nothing to see.
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Servers
Everything — including your cycle predictions — is computed locally on your device. There is no cloud copy of your data anywhere, so a data leak is mathematically impossible: there is nothing to leak.
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Ads & clutter
No intrusive pop-ups, no spam, no awkward content. No “wellness” upsells between you and your own body. Just a calm, fast app that respects your peace of mind.
Other trackers promise not to look at your data. Cykel is built so that looking is not possible.
The app
Six screens. One rhythm.
Recorded straight from the app — every pixel below runs offline.
Your day at a glance
The Today screen greets you with your cycle day, current phase and what’s ahead — a living ring, your week strip, and quick cards for mood and next period.
Every screen · light & dark
Try it right here
Working demos, zero data sent
These two phones run in your browser the way Cykel runs on your phone: locally.
C
Ask Cykel
Offline · Private
How are you today?
Flow
Symptoms
Mood
Saved on this device
🔒 Encrypted local database — nothing was uploaded
Your data, your device
Privacy isn’t a feature.
It’s the architecture.
Most trackers send your cycle to their servers and ask you to trust their policy. Cykel removes the server. Your logs live in an encrypted database on your phone; predictions, charts and the assistant all run there too. The only thing that ever leaves your device is an anonymous crash report — never your health data.
No cloud sync
No analytics on your health data
Biometric / PIN lock
Screenshot blocking
Local backup & export
Delete everything, anytime
Your phone
Your logs
↓
Encrypted database
↓
Predictions · Charts · Assistant
No cloud. Ever.
Everything you need
Built for understanding,
not engagement metrics
Smart predictions
Next period, ovulation and fertile window estimated from your own logged cycles — with honest confidence levels, computed on-device.
Phase-aware calendar
Month view colored by what your body is doing: menstruation, follicular, ovulation, luteal.
Insights that grow
Cycle length, sleep, weight, mood and symptom frequencies over 3–12 months. Pattern detection flags what tends to precede your period.
Ask Cykel
An offline assistant that answers from your history — last period, averages, regularity — and points you to a clinician for medical questions.
Gentle reminders
Upcoming period, late period, fertile window — local notifications at the time you choose. Nothing pings a server to ping you.
Yours to style
Light and dark, five palettes, nine fonts, living ambient scenes. Premium feel without a premium data grab.
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On-device storage
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Accounts required
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Symptoms & moods
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Ads, ever