Obviously, if you want to install on an iOS7 device you have to have a setup that allows for that which is an Apple thing.
I meant “you” as in “the application developer” and “install” as in “transfer the .app bundle from a Mac to an iOS device after building it” because I was speaking in the context of building applications.
I’m sorry if it wasn’t clear that none of this discussion has anything to do with people downloading apps from the iTunes Store. And, to reiterate, if the problem you are worried about was real, I think you’d have heard about it by now.