drip. menstrual cycle and fertility tracking

Open-source, non-commercial and leaves your data on your phone.GPL-3.0-only

Periodical

Menstrual/period calendarGPL-3.0-or-later

Bluemoon

Open source, privacy friendly menstruation tracking app. Your period, your data!GPL-3.0-or-later

Mensinator

Tailored Period Tracking, Total Privacy—Your Period, Your Control.MIT