This is actually an interesting question. In a lot of these examples, "app constellation" means everything the website does is too complicated so it needs to b

This is actually an interesting question. In a lot of these examples, "app constellation" means everything the website does is too complicated so it needs to be broken down into several different apps. It's possible that this is just a bad question. Apps originally designed for mobile don't have problems that you would consider solving with an "app constellation." They just don't have more features than comfortably fit into a mobile app. Tinder vs OKcupid. Twitter/Whatsapp vs Facebook. Skype vs Whatsapp. I mean, the mobile only (or first) essentially solve the same "problems." So Facebook needs to solve some hard, ugly problems that will probably never have a tidy resolution while whatsapp doesn't. No wonder they bought them. It's hard to move to less complexity. Just to give one example. FB (or Google+) need to give their users complicated privacy controls to decide who sees what. Twitter or Whatsapp don't, most of it is implicit.