You know, I think the best way is to open your ducati.ms and post from your phone. I believe that it sends a pop up message stating that there is an app and directs you to it from the phone to the app store.
This is the app. You might be able to download it from that page too.
Every time you log in from your phone on any forum that is part of a motorcycle.com it should prompt a suggestion of an app. I have a Verizon iPhone too. The app is called motorcycle.com just type motorcycle in app search, its a red icon with lettering motorcycle.com