CardDAV. I host this end-to-end encrypted on https://www.etesync.com/ https://www.etesync.com/ . I sync to my Android phone with the etesync app. I use the A

CardDAV. I host this end-to-end encrypted on https://www.etesync.com/ https://www.etesync.com/ . I sync to my Android phone with the etesync app. I use the Android contacts app to manage details. I don't keep detailed records. Just contact details, how I know them, name of children, etc.