Apps that use iCloud can now be transferred to another developer in the Apple Developer Program.
Apps Using iCloud
If your app uses any of the following, it will be transferred to the transfer recipient after they accept the app transfer.
● iCloud to store user data
● iCloud containers
● KVS identifiers associated with the app
If multiple apps on your account share a CloudKit container, the transfer of one app will disable the other apps’ ability to read or store data using the transferred CloudKit container. Additionally, the transferor will no longer have access to user data for the transferred app via the iCloud dashboard. Any app updates will disable the app’s ability to read or store data using the transferred CloudKit container.
If your app uses iCloud Key-Value Storage (KVS), the full KVS value will be embedded in any new provisioning profiles you create for the transferred app. Update your entitlements plist with the full KVS value in your provisioning profile.
More details on transferring an app can be found at the link below...