title: Can an iOS app file be updated while the app is still in review?
body: <p>Is it possible to update the file after initial submission of an iOS app to the app store?</p>
  
  <p>We have a stable version of a new app ready to submit but wondering if we can post an update with new features even while the app is under review after few days of initial submission.  Or do we have to wait for the app to be approved first to submit an update?</p>