Google Play

• Go to payments.google.com and log in with the account you used to make the purchase.
• Select Transactions to view your purchase history.
• Click on an item in the list to see the receipt for that individual purchase.

iOS

• Open iTunes on your computer.
• Click Sign In and enter the Apple ID and password you used to make the purchase.
• Click your name and select Account Info from the menu.
• Enter your password again.
• Scroll down to Purchase History and click See All.