Initially I thought this would be a one-time entry thing. But then I thought that it be nice to track gender over time. I.e. sliding each day over a month would give you an average of how you felt that month.
Then I realised that if other people were going to do this, then I didn't want to know what their average meant nor their gender nor anything else. So I decided to replace the specific gender values with colours. So you slide between two colors, their meaning is up to you, and at the end of the month you get a "average" colour.
Ironically, it seems, that there is a real need for such a slider. A child of a brother-of-different-mother would love to use it but because it's not an app (i.e. iOS dungeon ..err.. market or Google cave ..err... store) she won't use it (its just a web page - in fact a large SVG). Basically it needs to be a button on the home screen (I know, browser can put bookmarks on screens but try explaining that to a non-tech teenager).
I really don't want to get into building apps for android nor iOS, so if anyone is interested in doing this, then please do.
Monetisation would definitely not come from selling data (even that isn't possible in the current implementation [1]). A couple of things I was thinking about was perhaps being able to change colour would a premium feature. Or perhaps using a circle, i.e. 2 dimensional sliding could also be premium.
But of course, the premium feature that would be the cash cow would be an edit button ... if you forget to slide on a particular day, then you pay to change history.
Anyway a semi tongue-in-cheek write up[1] and the webapp[2] are both available. Thanks for reading this far!
[1]=https://gregorius.rippenstein.art/works/slider [2]=https://gender.sldr.in