There will be blood. Lots of blood.
Also I’ll be mentioning the P word, the M word, maybe even the F word.
I’m referring, of course, to periods, menstruation and monthly flow.
All the men stopped reading? Typical.
Two things:
1.
Long story: I keep track of my periods the old-fashioned way – with a physical calendar. In fact, this record-keeping is probably the only reason I buy a calendar every year. But I’m starting to use Google Calendar a lot more now, and it’d be nice to see it all online. Also, I usually predict my next round of non-stop bleeding by assuming that my period lasts 28 days – a very inaccurate estimate, given that I almost always start early. My period probably lasts around 24 days or so, but there’s no way I’m going to sit down with my calendars from the past couple of years and log that data.
Short story: I want an app that keeps track of my period, predicts my next period, and integrates with Google Calendar (or some kind of online calendar).
There are a couple of websites and apps out there that do some of these, but many are either badly designed or just plain misogynistic. And I haven’t seen any that sync with other online calendars.
So here’s a quick napkin doodle of what I have in mind:
The black graph shown in the first week (a period graph) would show two things: the rate of flow and the duration. Both are important things to know, but most apps typically show only the latter. Perhaps you have the option of adding details, like the rates at specific times, to increase the granularity of this graph?
One can imagine having similar graphs for symptoms that can be measured with a continuous scale, such as cramp severity. Discrete symptoms such as a change in the sense of smell (it’s either present or not present) can be indicated with symbols.
The second set of dark shadings at the bottom is supposed to predict when the next period will start. I’m not too sure about this part; when I drew this I thought of using the saturation to indicate the probability that the period would start on a given day: the more saturated, the greater the likelihood. But there are probably better ways to indicate that: maybe a ghosted-out period graph, with the shape and duration of your average period graph?
Given that the app would be integrated with a general-purpose calendar, all this information would have to be conveyed in a way that takes up little visual space. Perhaps lines can be used instead of solid blocks of colour? In Google Calendar there’s always the option to turn calendars on and off, so hopefully it’s not that big of a problem.
There is a lot of other information women could find useful: when am I most fertile? When am I least fertile? Does my period really cause more acne? Perhaps fertility and symptom information can be options that users can turn on and off.
Anyway! Lots of possibilities. 
2.
There are men who avoid the topic of menstruation like the plague. You say the M word in front of them and they shut off immediately, they try to change the topic, they look at you like you’re being incredibly rude for talking about something you have to undergo for a quarter of your life. Sure, it’s kind of gross, and nobody wants to hear the details, but can you at least be a little sympathetic about the fact that losing blood for up to a week can be uncomfortable and even painful?
How much do men know about a process that affects every single woman in their lives? In my experience: very little. I had a male friend who asked, innocently enough, why we can’t just “hold it in” until we go to the toilet. He was 21 at the time. At least he bothered to ask, but how many do?
And there really is a broader issue here: when the people who make things are predominantly of a certain gender, race and age, they tend to make predominantly things that appeal to people of a certain gender, race and age. Making them aware of this can go a long way, but there’s another solution: involve more types of people in the business of making things. More racial minorities, more seniors, more handicapped people… and more women.