Baby Companion

The problem

With a newborn, the questions never stop. When was the last feed? Which side? Did they sleep? Is this weight normal? With two parents taking shifts, the answers end up split between two memories and a few chat messages.

Commercial baby apps solve part of this, but they send very personal data about a child to someone else’s servers. I wanted one shared, real-time picture for both of us, kept entirely at home.

What it does

Feeding that both parents share

A breastfeeding timer that remembers the side and keeps running across both phones, plus bottle and pumping logs and a countdown to the next feed.

Fast logging

Sleep, nappies, temperature, medication and observations in a couple of taps, with optional photos.

Growth on WHO charts

Weight and length plotted against WHO percentile curves.

Agenda and development timeline

A calendar with bath days, medication and the commonly cited development "leaps", clearly labelled as broad estimates, not medical predictions.

Assistant that runs offline

Answers common questions using a curated knowledge base and the baby's own logged data, with no external service.

Architecture

In words

Both phones run the same installable web app and connect privately over Tailscale.

Every log is saved once on the home server and pushed to the other phone straight away, so a feed started on one phone shows as running on the other.

Data and photos live outside the application folder, so updating the app never touches them. Backups run separately.

How I built it

The requirements came from real nights. Logging had to be possible one-handed and half-asleep, and both of us had to see the same state without asking each other.

I designed the product, the data model and the privacy approach. The code was written with Claude Code, and I reviewed it. The interface is Dutch because we use it together at home.

Real use shaped it. The feeding timer moved from the phone to the server, so a feed started on one phone keeps running on the other. Lock-screen shortcuts made logging possible without opening the app.