Does the app work Offline or Not?

Yes it does work offline and your users will get a good user experience. Your app would connect to the data center and gets the new updates and installs that to cache. If your internet connection is lost, MobiRoller would detect that and your app would continue working with that cached data. When you regain access to internet, your app would continue working as it should. Certain modules would need internet connection at all times such as, twitter, youtube and catalogue. These modules would inform your users when the connection is lost.