I haven't tried this, but it looks like a good idea if you work in an insecure environment. Say at work where people might easily siphon off your data if you leave your computer unattended. Of course other security measures are advisable, like locking your screen when you step away from your desk. But the more layers of defense the better, in my opinion. I don't know how real the scenario is but you see people surreptitiously downloading files to a thumb drive all the time on TV shows and in movies. I'll be interested to see reviews from people who actually need and use this app. Just remember to use a hard password.
I give this app four stars even though I haven't tried it. It seems like one of those "why didn't I think of that" ideas, you know like ten years ago.