A mobile app is a downloadable application installed on a smartphone. It can be HTML5 based e.g. HTML5 website packaged as a mobile app or native e.g. developed in a coding language supported by the targeted smartphone’s operating system (Android, iOS, etc.). Once it’s installed most apps don’t require an Internet connection to run making the content available even when there’s no Internet connection. For an example of native mobile app have look at SMS Loc8.
Responsive Design, Mobile Site Or Mobile App?