Clue The European alternative to Flo / Glow

Clue is a cycle and period tracking app from BioWink GmbH, based in Berlin. Users log data such as period length, pain, spotting, weight, body temperature, and sexual activity. From this input the app generates predictions for the next cycle, fertile window, and period. The Clue Plus subscription adds further features including a pregnancy mode. Clue is aimed at menstruating people across age groups and life phases.

Clue is a Berlin-based company and falls under German and European data protection law. According to its privacy policy, all data is stored on servers located in the European Union. The named cloud provider is Amazon Web Services EMEA SARL, and only AWS data centres in the EU are used. This avoids third-country transfers for core data storage. That matters for a cycle tracking app handling particularly sensitive health data.

Clue distinguishes three categories of data. Health data includes period length, pain, spotting, weight, body temperature, hair quality, and sexual activity. Account data covers username, date of birth, and email address. Usage data includes device model, operating system, IP address, browser settings, app interaction patterns, and crash reports. Users decide which entries to make, and many tracking fields remain optional.