Is it possible to back up in-app purchases and game saves? Is it possible to back up in-app purchases (i.e. full game unlock) and game saves such that an iOS app can be deleted and later re-installed from the .ipa file? I'm using a 3rd generation iPad (model A1430; iOS 9.3.5). 

Edit: I had recently re-installed the game "Escape: Norm's World XL" by IUGO Mobile but it appears IUGO's server required to restore my purchase of the local multiplayer mode no longer works. I contacted Apple and they told me to contact IUGO Mobile. Unfortunately, IUGO Mobile hasn't replied to my e-mails. I was hoping there was a way to backup and restore (local game mode) unlocks to avoid this situation when replacing my iPad.
Normally apps that sell in-app-unlocks (as apposed to like packs of currency or the like) will have a button to restore purchases. This will give you the unlock again after it checks your account. 

It is dependant on the app though. IF the game has login system with a username and password etc, then it may keep track of the purchase from your login information.