Monitoring the FPS of a Direct X Application

Monitoring the FPS of a Direct X Application

I am looking to create an external application that monitors the 'FPS' or
a DirectX application. I have read several Microsoft articles on
performance measuring tools
(http://msdn.microsoft.com/en-us/library/windows/desktop/jj585574(v=vs.85).aspx#performance_time_measurements)
- but I am looking to get the feedback (and experience) of the community.
My question: what is the best method for obtaining the FPS or a Direct X
application?
I am using C# with Visual Studio 2012.