Cycle-synced medications

Most reminder apps can only repeat on a calendar. If what you take depends on where you are in your cycle, that is the wrong clock.

How it works

Pick a medication and bind it to cycle days or a phase instead of a fixed date — iron on the first days of a period, magnesium through the luteal phase, a painkiller a couple of days before PMS is due. The schedule then moves with the cycle, and the reminders move with it.

Who this is for

People with a cyclical prescription — PCOS and endometriosis routines, cyclical hormone therapy — and anyone timing supplements to a phase rather than a date. A calendar reminder cannot express a schedule like that. FlowByFlow binds the medication to the cycle itself.

Predictions that admit what they don't know

The cycle prediction is explainable rather than a black box: it widens its window when your data is thin and stays quiet when there is not enough of it, instead of inventing a confident date. Logging a period corrects it immediately.

The most sensitive data gets the same architecture

Cycle data lives on your device like everything else, and the app works without a connection. It carries no advertising SDK and never asks where you are, so none of this is feeding anyone's ad targeting.

FlowByFlow is not a contraceptive and does not provide medical advice or diagnosis. Cycle predictions are informational only — talk to your clinician about what you take and when.