iPeriod. Yep, you guessed it. A full-blown menstrual calendar. I'm crazy when I ovulate (aren't YOU glad you visited this blog today), but I'm practically high when my aunt comes to town. Go figure. So this explains a ton when my pants don't fit right and I'm overwhelmed at the idea of even ordering pizza for dinner.
What's great too is that you can record your weight and it charts it for you. I weigh myself every day. Before you go thinking it's crazy or obsessive, RealSimple mag listed weighing oneself daily in the top 10 methods of weight management. This works for me because numbers cannot lie. :)
This app makes me look so intelligent- whenever I go to any doctor appointment because I can answer exactly the date of my LMP! Steve Jobs, your influence is boundless.