I've looked into the following three options as being the most probable candidates for the top security apps on the market.
1. Leo Privacy Guard
2. AppLock
3. Advanced Protection
Advanced Protection is a nice app but it doesn't offer much besides app locking capabilities. If that's all you need then this app might work but you'll be missing out on a lot of other cool features offered by other applications.
AppLock is also pretty good. The only catch is that if you want access to all features of the app then you are required to download a premium upgrade. This costs money. We want to avoid spending money if at all possible.
Leo Privacy Guard is my personal favorite. The app is completely free and offers premium capabilities. You have the ability to lock apps, hide photos, hide contacts, hide apps, take selfies of snoopers, protect your phone from public wifi, & like a ton of more stuff. I really like the new selfie feature they added in the latest version. It programs your phone to take a selfie when it detects a potential security breech. This way you can go back to your phone later and see who was snooping. Pretty awesome I think!
