The apps are only from Samsung or more accurately through Samsung's services.
It's a walled garden. More at http://en.wikipedia.org/wiki/Closed_platform
I just bought SAMSUNG UE40H6400AKXXH smart tv few days ago. I have seen online that on some SAMSUNG smart TVs it is possible to play such games like NFS and get some other apps through Samsung apps but I wonder why I don't have Samsung apps on my Smart hub? I would really like to get some better apps than those odd puzzle games.