Review of Flo Period and Ovulation Tracker App In need of a period, fertility or ovulation tracker application, well do I have the perfect one for you. Flo is a free application that tracks periods, ovulation, fertility and even has a pregnancy mode. I downloaded Flo over two years ago and have yet to find a reason to stop using the app or switch to another period tracking application. Over my two years of using this application I have found it to be very accurate when predicting when my next cycle with start and end. Getting Started When you first download Flo you enter in information pertaining to your weight, age, when your last period ended, how long it lasted, and other data. Answering these questions accurately helps the application to predict when your next cycle will begin and when your ovulation day is. Trackers The application uses a monthly calendar to display when your ovulation day is and when your period should start and end. The dates that ...