To Delete a cloned app:
Long-press the app icon inside Parallel App and tap the X that appears on the top right of the icon.
This will remove the clone and the app icon.
If you've added any home screen shortcuts to this cloned app, you will need to delete those separately.
WARNING: Deleting a cloned app will remove the app and all related data, be sure you've registered an account or otherwise saved your progress before deleting the app. We are unable to assist with recovering any cloned app's data.