My Period Calendar is a free iPhone app developed by Sonya Marcarelli that helps women monitor and predict their menstrual cycle and fertile period. With this app, users can easily track their daily notes, moods, symptoms, weight, and other relevant information. The app provides useful insights into the user's cycle, and the data is kept private. However, users can generate reports to share information if needed.

What sets My Period Calendar apart is its accessibility with VoiceOver, making it a reliable source of information for visually impaired women. The app's interface is simple and user-friendly, making it easy to navigate. Overall, My Period Calendar is a great tool that can help women keep track of their menstrual cycle and make informed decisions about their health.