Womens Calendar is a free Android application developed by Sayrex, designed to help girls and women track their menstrual cycle and ovulation. The app allows users to input their menstrual data, including the start and end dates of their period, as well as the duration and intensity of their flow. The app also provides information about ovulation and fertile days, based on the user's menstrual data.

In addition to the basic tracking function, Womens Calendar allows users to record additional information about their health and mood, such as symptoms, medications, and exercise. The app also features a customizable interface, with a choice of color schemes to suit individual preferences. The app is easy to use and provides a comprehensive overview of the user's menstrual and ovulation cycle.