A free program for Android, by TZMO SA.

Bella is a menstrual calendar app that can be used by women to track the length of their menstrual cycle, predict when their next period is coming, and to know the fertile days of the month. It can also be used to keep track of the length of the menstrual cycle for the purpose of fertility management.

Bella is a safe, easy-to-use application. It can be downloaded and used for free. The app is designed to help women keep track of their menstrual cycle, and to know when their next period is coming.

This application will help you to make a note of every day of your cycle. Every day you can add a description of the symptoms that you feel. It is also possible to add your mood.