It works, that post you refer to is the old one. Rafael released a new version that is compatible with the Release Preview and still works in the RTM version as well.
You can find an updated post here and download the executable program here. The program requires you install the redistributable package of Visual C++ 2010. If you don't want to install it, I just built it not to depend on it.
It's actually quite useful to me, I use it to have a fast way to restart and shutdown the system:
And the procedure is quite simple actually:
Create a shortcut of what you want to have in that menu.
Rename it, set up its arguments, etc. Essentially finish it to your liking.
Drag and drop that shortcut over the program, or open a command prompt and run:
Open a explorer window and navigate to
%LocalAppData%\Microsoft\Windows\WinX, or input that in the run dialog (Win+R).
There you'll see group folders with shortcuts inside (and you can create more groups), move your shortcut to the group you want it to appear.
Restart the Explorer process from the task manager for example, or reboot.
After that the shortcuts will appear in the menu just like any other item there.
Here you have extensive information on how to customize it too.