Nexus is just the GUi for the Ipb-10.  Nexus doesn't make any sound by itself. So, I'd say "no".

Hey FlyingSquirrel,

  This is taken directly from the Digitech website about the Nexus app:

  "iPB-Nexus App allows you to control the powerful iPB-10 Programmable Pedalboard from DigiTech.  You MUST have the iPB-10 hardware in order to take full advantage of all the features and benefits of this application."

  So according to that statement, the application requires the Digitech hardware to be present in order for the App to function.