Berlin-based Clue, which makes an app that tracks a woman’s menstrual cycle through machine learning, has raised $20 million in Series B funding in a round led by Nokia Growth Partners. Existing investors Union Square Ventures, Mosaic Ventures, Brigitte Mohn and Christopher Maire also participated along with new investors Giving Wings and Fabrice Grinda. Previously, the company raised $7 million, and this latest round brings the company’s total funding to $30 million.

The funding will be used to continue developing the Clue app by making it smarter – adding more context to predictive notifications and deepening insights women can get from the data they enter in the app. Clue will also use the money to grow their team and ramp up marketing efforts. 

Clue uses an algorithm to calculate and predict a woman’s next period. Users add information such as the birth control they take (which they can also set reminders for), basal body temperature and level of flow, and they can also enter additional information such as mood and sexual activity.

Making Clue smarter has been the company’s focus for awhile. During their last funding round, Clue CEO Ida Tin told MobiHealthNews the company was looking to make their predictions more accurate with the advent of more tracking categories. In September 2015, they added 23 new tracking categories that range from food intake, skin health, mental health, medications, activity, energy and more.

Last year, Clue partnered with several academic institutions (Stanford, Columbia, University of Washington and the University of Oxford) for female health research projects. Topics included menstrual bleeding patterns with respect to age, and the impact of birth control.

The startup launched in 2013 with the goal to track ovulation cycles, but users of the app began applying it to many other aspects of their reproductive health, including mood and libido. As the company has evolved, CEO Tin points to the rise of “Femtech,” a category of products and services that addresses female health needs with technology.

“I feel as strongly as ever that Clue’s mission is to keep female health and its advancement at the top of the global agenda and I am thrilled to partner with prestigious investors who share our vision,” Tin said in a statement. “Healthcare is already going digital, just look at the 60 percent of smartphone users in the US using their devices to manage health. Female health is also driving this. And when you consider that more than half the world’s population is female, you realize how enormous the market potential and opportunity for Femtech companies is to truly make an impact.”

Clue is one of several reproductive health apps and products we’ve seen raising money and attracting a lot of users lately. Fertility service concierge company Progyny recently rebranded and launched a new website, wearable fertility-tracker Ava just raised money, and women’s and family health app maker Ovuline expanded its benefits business with an infusion of $10 million.

Tin herself spoke on TechCrunch Disrupt’s first-ever panel dedicated to women’s reproductive health. There, she spoke about the emergence of women working in tech, as well as a growing desire for data-driven insight about personal health. However, given the detail about this kind of data, these apps and tools must be implemented with a high degree of security and ethics. And it takes women creating these tools to understand that.

“I think it makes a difference when you have something happening in your body, and since most companies are started by men, it’s not been at the top of their mind,” said Tin at the time. “As more women are becoming tech entrepreneurs, it’s something we see happening.”