A free program for Android, by FUN MAKE.

Blossom is a free, comprehensive, and easy-to-use women’s health app designed to help women and their partners better understand their menstrual cycle, predict ovulation and fertility, keep track of their menstrual cycle, and track their fertility. It’s a comprehensive period tracker for women of any age, whether they’re just starting to have menstrual problems or are experiencing menopause.

The most useful period tracker for women and their partners, Blossom is more than just a period tracker. It also helps women and their partners understand how their menstrual cycle affects their health, predict ovulation and fertility, and keep track of their cycle.