iphone and ipad sync
is there a way to keep my ipad and iphone synced with each other so any change is automatically mirrored on the other device.
For Apple iCloud service just use the same ID for iCloud and turn on on each device the services you want synced.
Use iCloud on iPad - Apple Support
It is similar for iPhone.
For other services/app it depends upon the app. Some apps use login and may synce if same login used for the app on the other device. Some have no provision for syncing.