The app comes in two versions - free and paid-for - with the former featuring a series of in-program adverts. In use, the app is billed as having three main buttons: lock, file lock or shield pictures.
From the main lock menu users you can view a list of apps and choose those you want to protect, including email and messaging.
The file lock menu, meanwhile, opens a file browser, allowing users to tap-and-hold specific files and lock/unlock them as required.
The shield pictures feature, meanwhile, shows you a list of directories with photos in them, and allows you to check which pictures need to protect.
Infosecurity notes that App Lock will only operate if the app to be protected is active, so protecting files does not work if the app that `owns' them is not open.
It's also worth noting that it's also technically possible to uninstall the app to gain access to the protected files, but the app is useful for casual levels of security.
According to the AndroidTapp newswire, "one of the biggest bonuses of this lock application is the ability not only to lock applications and files but also the option to hide folders."
"By being able to lock files and folders on your SD card you can add a greater sense of privacy and security when accessing via the phone", the newswire notes.