Germany-based Clue has raised $2 million from German private investor Brigitte Mohn; French Groupe Arnault, the controlling shareholder of LVMH (Moët Hennessy - Louis Vuitton); the German pharmaceutical company DR. KADE; as well as executives from Spotify, Dropbox, and SoundCloud. This brings the company's total funding to $3 million.

Existing investors include Christophe Maire, Joanne Wilson, New York-based Luminary Labs Ventures, and Thomas Madsen-Mygdal. Clue raised its last round in February 2014.

Clue uses an algorithm to calculate and predict a woman’s next period. Users can add other information to the app, including updates on mood, sexual activity, level of flow, and personal notes. Users can also enter their basal body temperature, set reminders and keep track of birth control pill usage.

The app, available for iOS and Android devices, has nearly 2 million downloads from 180 countries. Clue Cofounder Hans Raffauf told MobiHealthNews that they will use the funds to add new features to the app, including a partner offering that provides a woman's partner with insights into her cycle, for example, if she has PMS symptoms. Clue will also add more languages to the app. It currently offers English, Spanish, Danish, German, Italian, and French. One of the new languages the company plans to add is Japanese -- Raffauf noted that only between one and two percent of women in Japan are on the contraception pill. 

"The reason behind [adding more languages] is getting more women access to Clue that don’t usually have access to sex education," Raffauf said. "For us, the reason to take it global is very much about women empowerment, education around the subject of sexual health and reproductive health, and also in some ways gender equality — which is also where the partner feature comes in, to raise the level of awareness around this topic in society. We can only do it if we have a global product and reach women who normally would not be reached by this topic."

The US remains Clue's biggest market -- 40 percent of Clue’s users are in the US. Clue is also in the process of developing an Apple Watch app, which they aim to release in April.

In February 2014, founder and CEO Ida Tin told MobiHealthNews that the company eventually plans to add more features, for example natural family planning as a method of contraception. Normally, when a woman wants to use family planning as contraception, she said, the woman needs to take her temperature and track her mucus very carefully, which Clue is not currently designed to do. But Tin added that Clue is developing hardware to help measure these metrics.

Clue graduated from Princeton, New Jersey-based accelerator Tigerlabs Health, an accelerator which aims to draw startups that want to work with pharma companies. Tin said Clue is eventually interested in working with them.

“Given that we are digital, there is a data set to what we’re doing that I think would be interesting for pharma,” Tin said. “There are possible distribution and branding opportunities [too].”