It is important to note that Apple and Google doesn’t charge twice for in-app purchases. Since you use the same user of the original purchase.

To restore purchases on Apple platform

1. First of all, delete the app from your device

2. Tap Settings in your device

3. Navigate to iTunes & App Store

4. Tap User and log out

5. Log in with the same Apple ID that originally purchased

6. Download the app again, tap Options menu and choose Restore purchases

7. Confirm your password if necessary

8. Get back to main screen and tap icons to download the content

To restore purchases on Android

1. First of all, delete the app from your device
2. Tap Settings in your device
3. Log in with your email (same used to purchase)
4. Download the app and tap Options > Restore purchases 
5. Confirm your password if necessary 
6. Get back to clips screen and tap icons to download