The short version: BabyRhythm has no server. Your baby's records live on your device and in your own iCloud. The developer cannot see them.
Nothing. The app contains no analytics, no advertising SDKs, and no tracking. It does not send your records anywhere, and there is no developer-operated server to send them to. There is no sign-up, so no name, email, or phone number is requested.
Records are shared only when you send an invitation yourself. Shared records stay in the inviter's iCloud, and invited people view them from there. You can stop sharing at any time; after that, new entries no longer reach each other. Participation is limited to people you invite — not to anyone who happens to have a link.
Apple Push Notification service (APNs) is used to learn that something changed in iCloud. The wording you see in a notification is composed on your device. Notifications can be turned off in Settings.
On some recent devices the app turns your records into readable sentences. That processing happens entirely on the device; records are not sent anywhere for it.
Reporting a problem opens your mail app and you send the message yourself — the app never sends anything silently. To help with diagnosis, the message is pre-filled with the app version, device model, iOS version, and sync status. You can see all of it and delete any part before sending. Mail received this way is used only to answer your question.
The app is purchased through the App Store and handled by Apple. There are no in-app purchases. The developer never receives or stores payment details.
This app is a tool for caregivers. It does not collect personal information from children. Values you enter about a baby (feed times and amounts, diaper entries, date of birth) are stored only on your device and in your own iCloud.
Because the developer keeps no copy, there is no separate deletion request to send.
BabyRhythm shows your records and summaries of them. It does not diagnose or prescribe. Please discuss any health question about your baby with a pediatrician.
If this policy changes, the date at the top is updated. If a change ever expands what is collected, you will also be told inside the app.