Luna: Private Cycle Tracker

Luna is the period and fertility tracker that keeps your most personal health data exactly where it belongs — on your device. No accounts. No cloud sync. No data sharing. Just intelligent, private cycle tracking powered entirely by on-device machine learning. YOUR DATA NEVER LEAVES YOUR PHONE Luna was built from the ground up with privacy as the foundation. Every prediction, every insight, every log entry is processed and stored locally. We can't see your data because it never reaches us — not even anonymized. SMART PREDICTIONS, PRIVATELY POWERED Luna's on-device ML model learns your unique cycle patterns over time, delivering increasingly accurate predictions for: Period start and end dates Fertile windows and ovulation estimates PMS and symptom pattern recognition Cycle length trends and irregularities TRACK WHAT MATTERS TO YOU Daily symptom and mood logging Flow intensity and duration Basal body temperature (BBT) Cervical mucus and ovulation signs Intimacy and contraception notes DESIGNED FOR EVERY BODY Luna adapts to irregular cycles, post-hormonal transitions, perimenopause, and more. There's no "normal" cycle — Luna learns yours. BUILT FOR TRUST At a time when reproductive health data has never been more sensitive, Luna takes a firm stance: what happens on your phone stays on your phone. No account required to get started. No subscription needed to unlock your own data.