OBJECTIVE: After comparing the top 10 menstrual tracking applications, there are no applications that address symptoms specific to Polycystic Ovary Syndrome (PCOS). This thesis demonstrates the need for a comprehensive menstrual tracking application that caters toward all populations, including patients with PCOS. METHODS: Mobile application usage was evaluated through data from the Ovulation and Menstruation (OM) Health Study to view relationships between PCOS/demographic groups and preference for tracking methods. The top 10 most popular mobile menstrual tracking applications were compiled through a search on the iOS operating system. Mobile menstrual tracking applications were then evaluated through an adapted APPLICATIONS system, which includes categories to score for PCOS-specific symptoms. RESULTS: PCOS groups showed clear preference for tracking methods overall, and are more likely to view their own health as fair/poor. P values for tests between other demographic variables in the OM Health study were insignificant, but there are observable trends in education, income, and age and usage of tracking methods. Evaluation of the top 10 mobile menstrual applications resulted in Clue scoring the highest, but no applications scored a complete PCOS-specific score. CONCLUSIONS: With continual variance in menstrual cycles, there needs to be development of a mobile menstrual application that is effective for all populations. Mobile menstrual applications have proven their popularity through PCOS groups and the rising usage within younger age groups. However, through the adapted APPLICATIONS system, major features are still missing, and are necessary to cater towards unique groups such as people with menstrual irregularities and PCOS.