A while ago I made an app for tracking baby activities because I became a parent and was horrified at how many permissions the existing apps required and how much tracking they contained. Both the app and the server are open source.
This is a web-app which also has an Android version in the Play Store (F-Droid didn't accept it because they don't feel like web-apps should be welcome in their store). On iPhones it can be installed as a PWA to the home screen.
Features:
No tracking whatsoever
End-to-end encrypted, no personal information is stored on the server unencrypted
Track baby's feeding, diaper changes, breast pumping and sleeping (more to come)