If what you have in mind is that your users manage their own authorization to published apps, using QlikView Administrators (adding users to the QlikView Administrators group on the machine) and Document Administrators (managed from QMC) I believe you'll be able to achieve what you're looking for.
On a quick search, I've found this pdf that I believe can help you:
Hope it helps.
Sorry for the double post.
For what I see, the pdf only describes the Document Administrator role for the Source Document folder. The process to access the User Documents folder is exactly the same only in the QlikView Server service.
But above that, do you have a Publisher license?
All this security features are disabled without a Publisher license.