There are plenty of apps which allow you to lock your apps. Protected Apps stands out by using xposed framework to allow you to configure your apps locks instead of just doing a blanket lockdown. This is pretty convenient. We have all been in the situation where a friend has asked to bum your phone to make a phone call or someone has used your phone to take a picture. It is nice to be able to eliminate the temptation of your friends to plunder through your device and personal info.
With Protected apps you are able protect any app with a password or PIN pattern, you can set a specific unlock time so if there is a time of day you know you will be alone you can set it to not lock your apps, auto locking can be switched off, you can set notification options, plus lots of other features. Head to the link below for the download.
Via XDA