German-based Clue is a popular choice. Take the guesswork out of your menstrual cycle with Clue a period tracker app that uses science and research to dive into your personal biology. Top 5 Period Trackers And Why Men Should Be Using It As a result it has set the tone and practice of many of the newer apps. Best app to track menstrual cycle . 2 Best for Health Info. Just like other womens smartwatch here the Garmin Lily smartwatch has a feature for womens physiological health. As far as menstrual cycles the FitBit app tracks mood protected or unprotected sex ovulation test fluids and other events the option given here is the morning after pill. Period Tracker Period Calendar has an incredibly forgettable name and its a little. With nearly a million users Clue is one of the most popular and well-trusted period tracking apps out there. The blessedly non-pink and data-centric app has over 25 million users worldwide. With the aid of a Garmin connect app you can track