Big big risk here having spent last 6 years working for the largest provider of adult live porn cams, FOSS isn’t the issue but regulation and safety and infrastructure to ensure everyone participating is a consenting adult and not being trafficked or abused is a huge problem around the world. I may incur downvotes for this opinion, but this is a space where it SHOULD be regulated with a lot of checks and balances. You don’t want to accidentally come across CSAM and have that cached in your temp files for so many reasons.

Bodies don’t have a set schedule for things. An AFAB body is supposed to routinely ovulate and have a period, but lots of things can disrupt that and cause things to happen early or not at all or delayed. Tracking becomes important for a lot of medical reasons, but a common situation in which it’s important to track is for conceiving. And yes privacy is a huge risk with using an app to track, and with how the government in the US is currently talking about punishing women for not conceiving or having miscarriages etc

Ex-employee of a large provider of adult content. Everyone’s hailing around similar things that are more or less accurate (fosta/cesta, csam, puritanical values, PNC Chargebacks) but follow the money back to who owns the CC providers and where they’re located and you’ll see the cultural acceptance of sex work is different and while they want porn money they ultimately don’t like sex work and that’s why they’re a pain in the ass so they have a number of options to to talk themselves out of offering transactions for whenever they feel ick’d about porn