This is a simple application designed to demonstrate a method of redirecting a single reactive app to a custom domain. It creates a site property called "Custom Domain". For testing purposes, you can go to Service Center, open the module and change the value.
Since the redirect is disabled in this application, you can put any value you want in the property - you don't have to own the domain. You will see whatever you put in the value displayed on the homepage to demonstrate how the process works. A message will appear telling you where the user would be redirected or starting that no redirection is needed.

There are comments in the Menu OnReady event describing how to implement this if you choose to use it for non-demonstration purposes.

The home page also uses its OnReady event in order to display the values on the page. This is purely for demonstration purposes, so that you can change the value in Site Properties in the module in service center and refresh the page and see the difference in the Custom URL field.