I don’t know if you’re someone who’s not had to deal with menstrual cycles, but that’s not really helpful advice. Apps provide a lot of useful information and often integrate with other health data to offer better predictions and general insights. Many cycles are not “oh, it’s the 15th, here we go”. Many can be affected or predicted by mood/diet/symptoms. That’s a lot for a person to keep track of. My app will sometimes predict up to a 3 day shift and be completely accurate. I have looked at the graphs and sometimes you can point to a specific symptom and say, oh that must be what it used for that prediction, but sometimes you can’t. Get stressed every year around the holidays to the point where it changes your cycle? Your app will remember that. One less thing for your stressed mind to worry about. Additionally, even if they were super regular to the day, having an app to send a reminder, “hey! Get ready tomorrow” can be helpful to make sure you have any supplies you may need.

Also, we use apps for things we don’t need to all the time. And generally, it’s for the same reason: apps are easier and more accessible. Since you mentioned a journal, there are plenty of apps out there that replace journals themselves. They are used for several reasons, but one would imagine using an app is easier because it’s not an extra item you have to have on you and can potentially lose or forget to bring, it’s always on you so the resistance barrier is smaller, it might even have search functionality.

Do I think people should be randomly downloading these apps? No, it really doesn’t do anything at all. But blaming people for using conveniences because the government is trying to take away their rights is really missing the mark. It might be good opsec, but it’s dismissive at the least and not really solving the actual problem.