Wouldn't it be better if iOS supported app-based plugins instead? It would make much more sense to me to download the Facebook app and then get the appropriate system-wide features, even when I am not using the app directly. I don't like this approach for two reasons. First, if I don't use Facebook, I will be stuck with unnecessary Facebook integration. Secondly, why is Apple making the choice for us? It's not that Facebook is the only social network.