I was about to throw my arms up in the air and give up on technology when I first heard that Apple expanded its HealthKit app in iOS 9 to track sexual activity. My initial thought was, “Oh great, like I really need Siri telling me ‘You're doing it wrong, she doesn't like that’ or ‘Try pulling her hair for a better response.’” Awkward, right? Thankfully, that's not the sort of thing that will happen (well, not yet anyway).
It's actually a lot more useful and less uncomfortable than that. There's a Reproductive Health category that's being added to HealthKit and it contains half a dozen subcategories. They include Basal Body Temperature, Cervical Mucus Quality, Menstruation, Ovulation Test Result, Sexual Activity, and Spotting.
Obviously this is geared towards women's health, though it can come in handy for a couple trying to procreate. Likewise, it can help someone avoid a pregnancy if they're not yet ready to take on the responsibilities of raising a child. It can also help prevent sexual diseases -- in the Sexual Activity section, users can note the date of intercourse and whether or not they used protection.
Naturally most folks don't want their sex lives broadcast to the world, especially when it comes to details like frequency of intercourse and if they're using protection. By default, all that information is kept private, though it can also be shared with a doctor or submitted anonymously to universities and physicians conducting research.
Tracking reproductive health isn't new to the mobile world. There are existing apps and devices that offer similar functionality, and it's said that HealthKit will work them as well.