TBH, I'm kind of surprised Apple is totally cool with this since one of the AppStore guidelines is to not create apps that replicate core iOS features. Now I know that Facebook's Camera app does more than take photos, but they are a direct replacement for the Camera and Photos apps that are native to iOS. Making the name and icon so very similar is close enough to be construed as an obvious intent to confuse/mislead.
I noticed that when changing the location settings in "Settings". The default Camera app was listed immediately next to Facebook Camera, confused me for a moment.
I wonder if Apple will make them add "Facebook" to the app name to avoid confusion, since it's the exact same name currently.