Applock DoMobile is very good, too keep things private, and safe from others you can use this application.
The interface of the application is very user friendly, you can customize through the option as you want. The application dosen't consume oo much RAM or system memory.
Installation process is very easy, just download from the playstore.
In this application you can set password to the applications which you want to keep private as others would not be able to open these applications. And also this app can be set as private so that others will not be able to uninstall or crack the application.
This is one of the most needed apps, I recommend this to everyone.