After purchaing a license from this website you will receive an email containing the license name and code - as below. Note how the name is actually the email address.

license-email.png

To register the app (and remove the trial period) you must launch the app then choose the Preferences menu option and enter the name/code in the License tab then press 'Register' - as below. Please note that the name and code are case sensitive and must be exactly as they appear in the email.

license-prefs.png