Most of us have chosen a password or pattern lock for your android gadgets. We might need to set a lock for a specific application. There are many downloadable applications that will fulfill this need.
But we suggest you ZDbox, for the good appearance and the user-friendly interface.
After installing the app on your phone, open it and go to the section where you choose between a password or pattern for your phone lock.
Now you can pick which applications to lock or unlock.
In the Settings, you can define a mode where it will ask you a secret question in case you have forgotten about your password.