Desktop messaging apps haven't gotten much attention lately. Sure, you continue to see mainstays like Skype, but the big chat services still tend to steer you toward websites. That might be changing shortly, however. A TechCrunch tipster has provided both an image and details of what looks like a native, pre-release Facebook Messenger app for the Mac. It's really the iOS app writ large, but it suggests that Facebook might be willing to return to the desktop after its relatively brief, ill-fated experiment with a Windows app years ago.