About Rhythm

Why this exists

I used BabyBuddy and found myself staring at charts trying to figure out "How long will he be down", "When should I put him to bed", and "Which day is this most similar to? How did we feel that day?". That's all time-chunked pattern matching, so I moved the same process into an app.

What I believe

Your data is yours. Rhythm is local-first. Everything runs on your device by default, including analytics and predictions. I don't see your data unless you choose to sync it, and even then you can encrypt it so I can't read it.

The app should work when you need it most. That's usually 3 AM, half-asleep, holding a baby. Midnight Mode exists because a bright screen at that hour is hostile. One-swipe logging exists because fumbling through menus while nursing is not a viable workflow.

Transparency over black boxes. When Rhythm suggests a wake window, it shows you which data points led to that suggestion. If you think it's wrong, you can adjust it. I'd rather you trust your own instincts with data to back them up than blindly follow an algorithm.

Honest pricing. The full app is free on one device. For $5/month, you get sync, backup, and household sharing. That's it. No "Basic" tier that's missing half the features. No ads. No trial that expires.

How it's built

Rhythm is a progressive web app. It runs in your browser and can be installed to your home screen. No app store needed. It works on iPhones, Android phones, tablets, and laptops. It works offline. It updates without you having to do anything.

The sync infrastructure uses CouchDB with optional end-to-end encryption. Data is replicated across servers in separate geographic regions so one going down won't stop your sync. Analytics and predictions run entirely on your device — nothing is sent to a server for processing.

Who builds it

One dad, working every night while watching the baby monitor until he needs me. Some nights I work for a few hours, some nights he needs help as soon as I sit down.

If something is broken, I want to hear about it. If a feature doesn't make sense, I want to know. Email support@rhythm.baby.