While I (just like the vast majority of readers of this comment) am not menstruating myself, the small sample of my three sisters (and, as it were, many of thei

While I (just like the vast majority of readers of this comment) am not menstruating myself, the small sample of my three sisters (and, as it were, many of their friends) seem to indicate that yes, tracking that information is more relevant to half of the human population than any other health metric is for men. If the question is "Why is there no menstruation tracker", the answer (really, the elephant in the room) is somewhere here: http://www.apple.com/pr/bios/ http://www.apple.com/pr/bios/. Of course, the unreleased data about gender diversity amongst Apple engineers, which we will hopefully get within two years by emulation thanks to Google's own interest in the problem, can easily be guessed as well.