Clue is a female health application that tracks period and fertility cycle. It uses science and data to provide actionable personal insights into female health. The free mobile app, available on iOS, Android, and Apple Watch, calculates and predicts users’ periods and PMS based on users’ data. It calculates fertility windows based on global averages, which can be made more accurate by users entering ovulation test data. Clue’s mission is to help people all around the world benefit from insights into female health. The startup was founded in 2012 and it is headquartered in Berlin, Germany.