But even before that, Levy argued, the “data-fication” of romantic and sexual behaviors was everywhere

There are strong assumptions built into their design that can marginalize a lot of women’s sexual health experiences,” Karen Levy, an assistant professor of information science at Cornell University, tells me in an email, after explaining that her period tracker couldn’t understand her pregnancy, “a several-hundred-day menstrual cycle

“Yeah, sure, [Apple] added period tracking, but you see some holdover effects of that,” she says. “You still have to use a lot of third-party apps to track women’s health.”

There have been free period-tracking apps ever since there have been apps, but they didn’t really boom until the rise of Glow – founded by PayPal’s Max Levchin and four other men – in 2013, which raised $23 million in venture funding in its first year, and made it clear that the menstrual cycle was a big business opportunity.

There were sex-tracking apps that quantified performance by counting thrusts and duration and “noise

By 2016, there were so many choices, surrounded by so little coherent information and virtually zero regulation, that researchers at Columbia University Medical Center buckled down to investigate the entire field. Looking at 108 free apps, they concluded, “Most free smartphone menstrual cycle tracking apps for patient use are inaccurate. Few cite medical literature or health professional involvement.” They also clarified that “most” meant 95 percent.

The Berlin-based, anti-fluff app Clue, founded by Ida Tin, would seem like an answer to this concern. It’s science-backed and science-obsessed, and offers a robust, doctor-sourced blog on women’s health topics. It arrived the same year as Glow but took several more to raise serious funding, provided mostly by Nokia in 2016. Today, Glow has around 15 million users and Clue has 10 million. There are still dozens of other options, but they’re undeniably the big two.

Levy coined the term “intimate surveillance” in an expansive paper on the topic in the Iowa Law Review in 2015. At the time, when she described intimate data collection as having passed from the state’s public health authorities to every citizen with a smartphone, she was mostly alone in her level of alarm. This was just after Apple Health launched (sans menstrual tracking), hailed as the future of medical care. There were smart pelvic floor exercisers that could pair with smartphones via Bluetooth. ”

“The act of measurement is not neutral,” Levy wrote. “Every technology of measurement and classification legitimates certain forms of knowledge and experience, while rendering others invisible.” Sex tracking apps and their ilk “simplify highly personal and subjective experiences to commensurable data points.”

Levy also pointed out that popular period-tracking app Glow, in addition to tracking menstruation and cervical mucus quality and other typical hallmarks of fertility monitoring, asked female users to log each time they had sex, including what position they were in during ejaculation. Glow Nurture, the iteration of Glow designed for pregnant women to track their symptoms, exercise, diet, prenatal vitamins, and so on, also fruzo reviews asked women to track their moods and provided a “mirror” app for the woman’s partner, which would ask them to provide an “objective” reading of that mood.

At the time of Levy’s writing, she described an app called iAmAMan, which allowed men to track multiple girlfriends’ periods at the same time, setting up alerts for when they could expect PMS or “horniness” or too much blood. (“Each girl can be set with their own separate password, so when you punch it in, it looks like you’re only tracking her,” the app’s description read.) That app has since been removed from the app store, but others have taken its place. I had no problem downloading and using one called PeriodMe, which will send me notifications when my roommates are about to start PMSing.