With Google Play the purchases should become available if you follow these steps:

 

1. Make sure that you are logged in with the account that appears on your Google Play receipt.

  • Open Google Play and tap the three bars in the top corner. 
  • Check the account that appears at the top of the menu.
  • If it is not the correct account you'll need to add it through the device settings.
  • Tap the drop-down arrow and choose the correct account from the list.


 

2. Launch the app, open the in-app Settings and tap the Restore Purchases button.