If it is only related to an image from a widget not showing in a mobile app, it could be the same issue that was there with one of my widgets; GoogleMapsCustomMarker. Make sure you do not use a relative widget path to an image in the widget folder, put refer to it via mx.appUrl. Not sure why this is not properly handled in a mobile app though, but below did the trick...
Changing the referral to the image in my widget from:
imagePath: mx.appUrl + 'widgets/GoogleMapsCustomMarker/images/m'