Sorry! It seems that there are some problems verifying the license.

Please uninstall and reinstall the app, or:

1. Wait at least 30 minutes. This is really important.
2. Type the Google Order number from the Google Play Order Receipt email. Usually it's a 15-, 16-, or 20-digit number.
3. Tap Verify License. If it fails, please email yukuku+hiq@gmail.com together with your email address used when buying from Play Store.

Once verified, you won't have to do this again ever.