We built Milo because we were terrified and could not remember anything.

He did not know how to eat

That is the part nobody had prepared us for. A baby who arrives early has not yet learned to drink — the suck, the swallow and the breath do not arrive in the right order — and the job in front of us was to get weight and fat onto a person who could not yet feed himself. Every millilitre was a small victory that had to be counted, because the counting was the treatment.

So we learned to nurse and to pump, in a week, on no sleep, at a hospital, without help. We had believed those were things we would learn slowly, later, at home.

And everything was a number

The doctors gave us targets and measurements: millilitres per kilo per day, grams gained since yesterday, how many nappies counted as reassuring. All of it revised each time somebody weighed him. We were two exhausted people trying to hold a clinical protocol in our heads between feeds, and we kept losing it — when did he last eat, how much did he take, was that before or after the weigh-in.

We started writing it on paper. The paper got lost, and being unable to answer a doctor’s simple question at nine in the morning is its own particular kind of awful. So we started building instead — first the one number we were asked for twenty times a day, and then the next one, and then the next.

The first thing we built, and still the first thing on the screen.

The charts were for our nerves

Feeds, nursing, pumping, weight — logged as they happened, then drawn against the curves other babies are on. And against the right ones: a baby born at 35 weeks does not belong on a term chart, so Milo plots the preterm bands until the due date and switches to corrected age after it. Watching a line climb back toward where it was supposed to be does something for you at 4am that no reassurance from a stranger can. It was never about data. It was about being able to stop being afraid for an hour.

The same log became the sheet we brought to appointments — weight and height against the WHO curves, intake per day, and the questions we had written down at 4am and would otherwise have forgotten in the waiting room.

Then: who do we call, and where do we go

One bad night we found ourselves searching the internet for the nearest hospital while holding a baby who did not look right. Nobody should be typing a search query in that state. So Milo learned the other half of the job: the numbers to call and the door to walk into, written down in advance, with his current weight computed live — a dosing weight is worth nothing if it is three weeks old — on every phone that is allowed to have it.

A gallery instead of a feed

Our friends and family wanted to see him, and we wanted them to. What we did not want was our son’s face on a social network, filed away by a company we will never meet, for as long as that company exists. So he has a photo a day, in a private gallery, for the people we invited — a grandmother sees it and nothing else: not the log, not the emergency card.

It has turned out to be everyone’s favourite part, ours included.

His picture is at the top of this page because we decided to put it there, and we could take it down this afternoon. That is the entire difference, and it is the one a feed takes away from you.

He is fine now

He gained the weight. He learned to eat. The app kept growing with him — every part of it exists because one of us needed it on a specific bad day, and none of it was designed in a meeting.

We are opening it up to other families now, slowly and by hand, because we keep meeting parents in the same week we were in. If that is you: it is free while it is small, and we answer our own email.