Cylla: Private Period Tracker

100% private period & fertility tracker. Zero cloud. Zero data collection. Track your cycle, fertile window, and symptoms — all on your phone. Your data never leaves.

Your body. Your data. Your phone. Period.

Cylla is the period tracker that collects nothing. No account. No cloud. No tracking you while you track your cycle. Every bit of data stays on your device — always.

PRIVATE BY DESIGN Most period trackers upload your intimate health data to their servers. Cylla doesn’t have servers. There’s no account to create and no data to breach. Your cycle data lives on your phone and nowhere else. Lock it with Face ID or Touch ID.

TRACK YOUR CYCLE

• Log your period with one tap
• Track flow intensity, symptoms, and mood daily
• See your current cycle phase (menstrual, follicular, ovulation, luteal)
• Get cycle predictions based on your personal history
• View your cycle day, phase, and stats on a beautiful dashboard
• Monthly calendar view with cycle phases and logged data at a glance
• Set your period start date flexibly — today, yesterday, or any recent date

FERTILITY & OVULATION

• Daily fertility level on your dashboard (low, medium, high, peak)
• Fertile window timeline shows your most fertile days at a glance
• Track cervical mucus, basal body temperature (BBT), and LH tests
• Estimated ovulation day based on your personal cycle length
• Smart disclaimer when hormonal contraception suppresses ovulation

JOURNAL YOUR HEALTH

• Daily health diary with mood, symptoms, and notes in one view
• Timeline shows your complete health picture day by day
• Delete any day’s data anytime — it’s your data

LEARN FROM EXPERTS

• 88 curated, evidence-based health articles
• Sourced from ACOG, Mayo Clinic, WHO guidelines
• Topics: cycle health, symptoms, nutrition, mental wellness, reproductive health
• 36 articles free, 52 with Cylla Pro
• Available in 12 languages

INSIGHTS THAT MATTER

• See your symptom patterns across cycles
• Track mood trends over time
• Monthly health summaries with real data
• Fertility insights with recent observation history
• Cycle variation and regularity analysis

DATA PRIVACY CONTROLS Your data, your rules:

• Reset all health data with one tap
• Option to start fresh with sample entries
• Protected by Face ID or Touch ID
• Complete control over what stays on your device

12 LANGUAGES English, Spanish, French, German, Japanese, Chinese (Simplified & Traditional), Portuguese (Brazilian), Korean, Hindi, Arabic, and Vietnamese.

CYLLA PRO Free: Full cycle tracking, fertility & ovulation tracking, symptom & mood logging, daily journal, calendar view, 36 health articles, Face ID lock, data privacy controls, all 12 languages.

Pro ($3.99/month or $9.99 lifetime): All 88 health articles, mood trends, monthly health summary, symptom pattern analysis, cycle alerts.

No ads. No data selling. No "anonymous" analytics. Nothing.

Subscription details: • Monthly Plan: $3.99/month • Lifetime: $9.99 (one-time purchase) • Payment is charged to your Apple ID account at confirmation of purchase • Monthly subscription auto-renews unless cancelled at least 24 hours before the end of the current period • Manage subscriptions in Settings > Apple ID > Subscriptions Privacy Policy: https://www.calmaxsystems.com/cylla/ Terms of Use: https://www.calmaxsystems.com/cylla/

We collect nothing. Zero. Your health data is yours alone.

This app provides general health information and is not a substitute for professional medical advice. Always consult your healthcare provider for medical decisions.