I can't read a single entry. Not one.

Not "I promise not to". I built it so that I can't. Your entries are end-to-end encrypted on your phone, with a key only your phones have, before anything leaves.

In plain terms: what I store is unreadable noise, and the thing that would make it readable never touches my server.

For anyone who wants specifics: AES-GCM with a 256-bit key, and that key is derived on your phone from your sync code: PBKDF2-SHA256 at 600,000 iterations, then HKDF-SHA256 to split the result into the key, a relay token and the six check digits. Standard Web Crypto, nothing hand-rolled.

What my server holds

Per sync code, that's the full list:

• Your entries, encrypted. I have no way to decrypt them.
• The order they arrived in, and when they arrived.
• A one-way fingerprint of the token your phones use to prove they're yours. Not the token itself.
• Whether this set of phones has been paid for. A yes or a no, and nothing about who paid.

No name, no profile, no analytics, no advertising anything. Not because I deleted them, but because I never built anywhere to put them.

Even the timing is hidden. The time an entry records lives inside the encrypted blob, so I can't tell a 3am feed from a lunchtime nappy change. Only that your phone sent something.

Your email address, and the £2

Buying it does involve an email address, because a receipt has to go somewhere. That address sits with Stripe and my email provider, and it isn't connected to your entries by anything on my side. I can't look up a sync code from an email, or the reverse.

Stripe handles the payment, holds the card details and sends the receipt. I never see the card.

The one join I could have built and did not: my server knows a set of phones has been paid for, but not which payment did it. Stripe knows which email bought which payment. Storing the link between the two would have joined your email address to your entries, so nothing here stores it, and buying it twice from the same address is the only way I would ever notice.

It gets deleted after 30 days

The server is a relay between your devices, not a backup. Each change sits there until the other phone collects it, then for a month, and then it's gone. Your phones keep the whole history.

The tradeoff: a phone left offline for more than a month misses whatever it didn't collect. In a house with two phones in it, that doesn't happen.

The key is yours and I never see it

Your sync code is what does the encrypting. It's generated on your phone. It isn't emailed, isn't attached to anything you buy, and isn't stored on my side in any form.

Which means I can't recover it for you. There's no reset link because there's nothing on my end to reset. Any phone you've already set up can show it to you, so it's only really gone if the code and every device go at once. More on that.

Things I don't do

• No accounts, so no password reset trail and no profile.
• No analytics. No "anonymous usage data". No cookies on this site.
• No trackers, ad networks or social login buttons.
• No selling your data, which would be a neat trick given I can't read it.

And nothing loads from anywhere else. The app used to pull its typeface from Google Fonts, which meant one request to Google every time you opened it. It uses the fonts already on your phone now, so opening Baby Brain talks to nobody but the relay.

Getting your data out

Settings, one tap, and everything downloads as a file you keep. No request to me, no queue, no waiting. Worth doing occasionally.

Who else is involved

• Cloudflare hosts the site, the app and the relay. They hold the same encrypted blobs I do, and like any host they see your IP address and roughly when you connected. I don't do anything with that and I can't tie it to your entries, but I'm not going to pretend it isn't there.
• Stripe takes the £2, holds the card details and sends the receipt. I don't, and there is no separate email provider to name, because nothing else on my side sends you anything.

Asking me things

Anything at all, including your rights under UK GDPR: allan@corbett.fyi. I'm Allan Corbett, based in Edinburgh, and I'm the data controller, which mostly means there's one person to shout at and it's me.

Worth setting expectations on what those rights can actually get you here. I hold your email address and a payment record with Stripe, and I'll delete or hand over either on request. The encrypted entries aren't tied to you by anything on my end, so there's nothing there for me to look up, hand over or delete on your behalf. Stop using it, wait 30 days, and they're gone by themselves.

Last updated: 2026-08-30.