I don't think it's available within crm, if it is this is a recent change.
Your options are
1)
Build your own sales presentation app which uses the data from crm. Or variations through to ignoring dynamics crm completely for this functionality.
Depending on what your sales literature is like this could of course be "just" giving someone a bunch of pdf, organised into folders so they can find something easily.
2)
Third party add ons. There are quite a number of these around.
I would look at CWR Mobility pricing and functionality.
http://www.cwrmobility.com/