Explored ELM's mobile site (Electronic Library for Minnesota). It was a good reminder of the databases ELM offers, and I added an icon to our iPad for quick access. We have links to most of the databases directly on HCL website so I usually access them that way.
Hennepin County has a mobile platform using Boopsie (but vendor may change.) The app is accessible in the lower left corner. BookLook allows you to scan a book's barcode at the store and see if HCL owns it. The mobile site has a Metrowide Calendar of events at all county library systems.
HCL uses apps for Overdrive (digital ebooks and audiobook downloads), Zinio eMagazines, Freegal music downloads. I use Overdrive on my Kindle Fire for ebooks and audiobooks. When I teach an ebooks class, the thing that trips people up the most is remembering to sign up for an Adobe Digital Editions account first. It is recommended that people check out ebooks through the full library website, not the mobile version.