There are millions of protective apps that are on the market, but only a few of them are actually effective. Master Key – Lock, Protect, and Manage Your Info is an app that provides exactly what it states. Since digital has become the way of life; passwords, pin codes, credit cards, passport information, and many other things vital to know. But, you can’t be expected to remember it all! This is why storing it somewhere without fear of it being seen is very important.