Cylune: Private Cycle Tracker

Cylune is a beautifully simple period calendar that keeps your cycle information on your device. Cylune works entirely offline, without ads, accounts, tracking, cloud storage, or external services. It is thoughtfully created with enduring care for women and deep respect for their privacy. View and edit all periods in one calendar. Tap any day to select it—and tap again to remove it. One missing day remains part of the same period; longer gaps create separate periods automatically. PRIVATE BY DESIGN • No account or sign-in • No advertising, analytics, or tracking • No cloud synchronization • No third-party health SDKs • Cycle entries stay in the app’s private storage CALM, USEFUL AWARENESS • Edit, add, or remove period days in one fast calendar • Adjust period length and rhythm • See unselected days predicted from the first logged day • Automatically complete elapsed days in an active period • Hold or double-tap any day to manage a private text comment • See the next likely date and confidence window • See the current period day or estimated fertility likelihood • Review confirmed and automatically estimated entries • Edit or delete accidental entries directly from history • Fill empty months in place, or confirm six-month prefill after the oldest record • Protect an editable pregnancy date range from automatic period estimates • Restore your last selected Extended or Simple view at launch • Learn from recent cycle patterns without complicated settings Cylune is designed for personal organization and general cycle awareness. Predictions are estimates. Cylune is not a medical device and must not be used for contraception, diagnosis, or treatment. Contact a qualified healthcare professional for medical advice.