This tool is compatible with:
Open the magazine app on the iOS device where subscription is active
On the homescreen of the app > tap on the Gear icon (bottom-right)
Copy the Device Token in the next screen
Email the Device token to yourself.
Open the email you sent yourself on the new device
Tap the Device Token to select and copy it.
Open the magazine app on the New iOS device
Tap the yellow Subscribe button > then select Current Subscriber
from the dropdown menu.
In the Account Number field, paste the copied Device Token