A free program for Android, by punchlinestudio.

This is an app for women who are trying to get pregnant, or who are pregnant and want to record the period, or for women who are just curious about their bodies and their fertility. It has a very simple and intuitive interface, so even if you have no experience with using a smartphone or tablet, you will be able to use this app. 

In this app, you can record the date of your last period, the length of your menstrual cycle, and the length of the luteal phase. You can also record the symptoms you experience during your menstrual cycle.