Image xBReeZ only stores the paths to existing pictures on your device while it processes them to enlarge them using the xBRZ scaling routine.
No data is uploaded to any server.
The app only rescales images that you send to it, and saves them back to the designated folder.
Here is a link to the app in Google Play Store:
https://play.google.com/store/apps/details?id=net.intrepidis.imagexbreez