Clue

Clue is a menstrual and reproductive-health app developed by BioWink GmbH, headquartered in Berlin (Adalbertstrasse 7-8, 10999 Berlin). Co-founded in 2012 by Ida Tin, Hans Raffauf, Mike LaVigne and Moritz von Buttlar, the app launched in 2013 and now has over 15 million users in 180 countries. Clue predicts periods, the fertile window and PMS, and lets users log over 30 health categories from sex and sleep to pain, exercise, mood, skin and digestion. The product is GDPR-compliant and emphasises science-based content; a free tier covers the basics with Clue Plus subscriptions adding deeper insights and modes for pregnancy and conception.