After reviewing some internet postings on Apple Support I determined that the best method was restoring from an iCloud backup. The reason is the iCloud backup retains your saved game app data. I had a very old version of AngryBirds Seasons on my old iPad. When it I tried to restore my saved games, this was the only game that would not restore. The restore process gave me a message that I would need to repurchase the latest game. Since it was free I downloaded the latest version. Afterwards I later discovered that my saved game results was re-populated to the latest version. Thank you Apple!