Hide Apps And Lock Apps is a free launcher that allows you to hide apps or lock apps using a variety of security measures. It makes some other, smaller changes to the basic interface as well, and integrates them with its security functionality.
As noted, Hide Apps And Lock Apps is a launcher, not just an app. Its app hiding and locking functionality is baked right into the launcher itself. That's why, when installing it, your lock screen will look different and your background may change. That said, in almost every respect Hide Apps And Lock Apps looks just like the default launcher; the only caveat is that you can't use its functions with another launcher. It lets you hide apps from view, and protect them with passwords and pattern locks.
For the simplest of needs
Hide Apps And Lock Apps is easiest to recommend if you aren't already using a different launcher, and you simply want to hide and lock apps very easily. Though as a launcher, it isn't of the highest quality, the fact it makes so few changes means that this will not be very noticeable to a basic user who just really, really wants to hide some apps.