A free program for Android, by Ennesoft.

Period Tracker Mia is an app designed to help women keep track of their menstrual cycle. The Period Tracker Mia app has elements that will assist you in predicting the start of your next period, cycles, and ovulation. You can also view information about your previous cycles and ovulation, calculate your fertility, and receive fertility and intimate partner notifications. You can customize the appearance of your Period Tracker Mia app and import data from the free version of the app. The app also allows you to customize your periods, set your cycle length and luteal phase, add medications, and examine cycle and fertility information. The tracker can also be started on a certain ‘First Day of the Week.’ Pregnant Mode is also available.