I have a Windows Phone and I use Fertility Diary (there are several others that I tried and this one seems to be the most cohesive and customizable) and I LOVE IT! I can chart just about everything from an Angry Mood to OPK to Intercourse to Weight, to Cervical Mucus, and it is SO customizable and easy to use, you can generate reports that will give you a breakdown of your cycles and help you really stay on top of your fertility. I am sure iPhone and Android have the same (or at least a very similar) app since they have been on the market longer and users have a much broader marketplace. I hope this helps.View Thread