https://www.theguardian.com/society/2020/dec/21/menstruation-apps-store-excessive-information-privacy-charity-says

Exclusive: Privacy International finds apps collect information on birth control habits or how hard it is for women to reach orgasm

Menstruation apps are unnecessarily storing personal data such as what medication women are on, their birth control habits and how hard women find it to reach orgasm, privacy campaigners have said.