Menstrual Ovulation Calendar is a lifestyle app developed by Grupo Precedo for Android devices. It is a free app that provides information about women's menstrual cycles, including their fertile days, ovulation, and period, to help monitor their monthly cycle using the Ogino-Knaus method. The app is based on the calculations and criteria used by the Princeton University in the United States, and according to different studies, the effectiveness of this method as a contraceptive reaches 80% in cases where used properly.

The app offers an ovulation calculator, menstrual period calculator, pregnancy and fertility calculator, menstrual or period calendar, and notes and menstrual cycle history. In addition, it also allows users to add notes on each day about anything they want to emphasize, such as symptoms, mood, temperature, taking contraception (pill), etc. The app is easy to use, fast, reliable, and optimized and tested by professionals. It is completely free, and users can use it daily and whenever they want. However, the app is for guidance only, and it should never replace the advice and indications of a medical professional.