A license for Porthole and AirVLC can be bought inside the app. They will automatically unlock in place. At the same time we dispatch an email with your license details to the email address you provided during your purchase.
Buying via the website works in much the same way. You will get a license key via email that you can enter in the latest version of your app, available from the website. After entering your license, the app will unlock in place, removing the trial limitations.
If it's an App Store app, Apple will take care of the purchase process. If you have any specific questions. Don't hesitate to ask.