Board Thread:Game Discussion/@comment-30244329-20180208184500/@comment-27370080-20180208230538

Michael has an excellent blog on how to run two different types of emulators, BlueStax and NOX, which will allow you to log in with your Google account, credit the cards, sync RR3 from your main device, buy the IAP, Cloud Save, then open your main Apple device again and Cloud Restore, the Google IAPs will then reflect in your Apple balance.

My preferred cloud save/restore service is Facebook- never had a lick of problems, and it's a great way to backup without having a second device.