Not great

The outlook used to look exactly like the calc app that comes with your phone. Since iOS 7 the outlook has changed to look nothing like the real calc.
Also, not user friendly. I came back to the App Store to find instruction on how to upload files into existing portfolios but it doesnt say.

All in all, yea this app "hides" files but not very good seeing as its hard to use and is not camouflaged well.

Nordisk Krigstromme about Secret Calculator for iPhone, v2.3