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.
 
 1.1 Open Google Play and tap the three bars in the top corner. 
 1.2 Check the account that appears at the top of the menu.
 1.3 If it is not the correct account you'll need to add it through the device settings.
 1.4 Tap the drop-down arrow and choose the correct account from the list.
 
 2. Delete and reinstall the app onto your device. 
  
3. Launch the app, open the in-app Settings and tap the Restore Purchases button.