Lunavi: Offline Period Tracker

Lunavi is a period, ovulation and fertility tracker that works entirely offline, with no account, no ads and no cloud. Every log, symptom and cycle prediction is processed and stored only on the phone, and nothing is transmitted, which is the whole point for people uneasy about sharing reproductive health data with a server.

It covers the usual tracking of periods, symptoms and fertile windows. Predictions are estimates based on your own history and become more reliable after several cycles; they are not contraception. Offline also means no sync between devices, so backups are your job when changing phones. Anyone who wants a capable cycle tracker without their data leaving the device should start here.