Ida Tin is the CEO and cofounder of Clue, an app that allows women to track their monthly cycles in a beautifully designed, decidedly "non-pink" environment. The app can help women prevent pregnancy, track the days of the month they are fertile, use personal data to understand their health, and communicate more effectively with health care providers. With more than 4 million active users, Clue is now a category leader in women's health apps. Fans are drawn to both Clue’s functionality and its sophisticated design, which avoids pastel and floral motifs in favor of knowing touches such as an image of gray clouds to represent days when users might expect PMS. Tin conceived the idea for Clue in her 20s, when she wanted to prevent pregnancy but preferred not to go on the pill because of the side effects. The three-year-old app is now generating a trove of useful information, which the Berlin-based company is sharing with researchers at Stanford, Columbia, and Oxford universities to glean insights into women’s health (the data is all anonymized, and users can opt out). Next, Tin plans to make the software available on feature phones, which would help women in developing nations with family planning. Prior to cofounding Clue, Tin was the owner of MotoMundo, a motorcycle touring company that led groups in Cuba, Mongolia, the U.S., Chile, and Vietnam; she published a book about the experience, Direktøs, which became a Danish best seller. She is a graduate of Kaospilot, Denmark's creative business school.