Track how your gender feels, day by day.
A lot of us feel something cyclical, on hormones and off them. Memory is a bad way to check. Fluidity asks a few questions a day, and after a few months tells you if anything repeats.
iPhone, iPad and Apple Watch. Coming to the App Store.
The app
Real screens, not mock-ups.
Today, and the last fortnight. 
The first question. 
Anything to add? 
What was found, and how sure it is. 
Every check-in, in order. 
What stays on your phone. 
Choose what to track.
Asks once a day
One notification a day, at a time you pick. Five questions, about thirty seconds. Femininity and masculinity are two separate scales, not one slider.
Offers the rest
Then one page asks if you want to add more: dysphoria, sleep, symptoms, libido, how the day went socially. Only what you pick gets asked.
Skips what doesn't apply
No hormone questions if you're not on hormones. Days since your last injection are counted against your own schedule.
Never suggests an answer
Every scale starts empty, with a small mark at yesterday's answer. A slider sitting at the middle is a nudge toward the middle.
It will tell you when there's nothing
Any series has a strongest frequency, so finding a cycle is easy. Not fooling you is the hard part.
- Handles the days you missed instead of assuming they were average.
- Significance measured against your own data, shuffled hundreds of times.
- Weekdays removed first, so a working week isn't a seven-day rhythm.
- Nothing claimed until thirty check-ins across twelve weeks.
- Links between measures corrected for every pair and lag tested.
"No rhythm found" is shown with the same weight as a finding. For a lot of people it's the true answer.
On your phone
How your gender, body and desire move is nobody's business but yours.
Face ID, if you want it
A lock you choose during setup, not one assumed for you.
Called "Fluidity"
The home screen is the one part other people see. It doesn't say what the app is.
Summaries on device
Written by Apple Intelligence on your phone. No server, and no summary at all when it can't run.
Yours to take
Export your check-ins as CSV. Delete them all. Whenever you like.
And on your wrist
The watch app only answers questions. Turn the crown for the scales. Start on the watch, finish on the phone, or the other way round.
Not out yet
Fluidity is still being built. There is no sign-up list — write if you want to hear when it lands, or watch the repository.
Who made this
One person, for a friend who was keeping all this in a spreadsheet. It sells nothing and collects nothing.