Okay, it puts aside the Windows Phone Design Language for a single screen of buttons, but this is not for a long and detailed exploration of the perfect Facebook Cover image, it's about capturing a moment and making sure that it's conveyed to everyone via Facebook.
Decide on the flash setting, point your phone to take the picture, and then hit the upload to Facebook button. It's as simple as that.
Perhaps there's an option for an advanced button, to allow you to load a picture already taken, or to alter the focus with a tap of your finger, or even Lens integration. Well, there is, but this is a quick utility, with one goal, and it's all the better for it.
Facebook Cover Cam is a free download via the AAWP App Directory.