YIMA: Period Tracking
Period Calendar
Only for iPhone
Free · Designed for iPhone. Not verified for macOS.
iPhone
YIMA: Period Calendar is a beautifully designed, privacy-first menstrual cycle tracker built with love by the Novawerk open-source community.
YOUR PRIVACY MATTERS
All data is stored locally on your device. No accounts, no cloud sync, no tracking, no ads — ever. You own your data completely.
SMART PREDICTIONS
Record just 2-3 cycles and YIMA automatically predicts your upcoming periods, fertile windows, and cycle phases with increasing accuracy.
CYCLE AT A GLANCE
• Visual calendar with color-coded period days and predictions
• Real-time cycle phase indicator (Menstrual, Follicular, Ovulation, Luteal)
• Countdown to your next period with day-by-day tracking
• Bar chart showing cycle length trends with outlier detection
DAILY LOGGING
• Track flow intensity (Light, Medium, Heavy)
• Record your mood and symptoms
• Add personal notes for each day
• Backfill past periods anytime
DETAILED STATISTICS
• Average period and cycle length over last 6 cycles
• Visual cycle comparison chart
• Complete history with period and cycle data
• Easily spot irregularities
THOUGHTFUL DESIGN
• Material Design 3 with expressive shapes and animations
• Light and dark mode support
• Smooth page transitions and delightful interactions
• Available in English and Chinese (中文)
OPEN SOURCE
YIMA is built by Novawerk — open-source apps, made with care. View our code, contribute, or verify our privacy claims at github.com/Novawerk/yimalaile.
This app does not provide medical advice. It is for educational and planning purposes only.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Smoother onboarding: the "currently on period?" step now adapts to your situation — supports an active period without forcing an end date, and seeds an anchor cycle if you're unsure so predictions still work.
Tapping "Period started" in the calendar now defaults to the day you just tapped on (within the past week).
The developer, Haodong Ju, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Haodong Ju
- Size
- 38.7 MB
- Category
- Health & Fitness
- Compatibility
Requires iOS 18.0 or later.
- iPhone
Requires iOS 18.0 or later. - Mac
Requires macOS 15.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 2.0 or later.
- iPhone
- Languages
- English and Simplified Chinese
- Age Rating
9+
- 9+
- Contains
Health or Wellness Topics
- Copyright
- © 2026 @ Novawerk