BranchOut works as an app in Facebook but its aim is slightly different from the regular FB applications. What we usually have in mind when thinking about Facebook apps are those designed to help us deal with our free time, are entertainment oriented and in general, become amusing applications to kill the time with.
But this one is different. BranchOut is the Facebook answer to Linkedin or Xing, and its aim seems to connect people for professional purposes, starting with your own Facebook friends network. Very much the same as the other two mentioned platforms. Oh, and you can even import your profile from Linkedin.