Security - How to add OAuth2 authentication to a WinForms app

This is another example of how flexible the security module and our framework are. My colleague Michael has recently published an example on how to use the Microsoft, Google, Facebook or any compatible authentication provider within an XAF WinForms app:
https://www.devexpress.com/kb=T567978
This implementation is based on public community resources like StackOverFlow, so research the links in code comments for more details.

If you are looking for an ASP.NET example, do not miss the article we published earlier:
How to: Use Google, Facebook and Microsoft accounts in ASP.NET XAF applications (OAuth2 authentication demo)

Your feedback is needed!
Originally, we were not going to make a WinForms counterpart, because there were only a couple of requests for it + the whole scenario looked rare for desktop apps.
What is your own experience with it? Have you ever had such integration requests from your end-users? What providers do they need to cover most? Please let us know.