9855 is your default password. This is similar to ios7 lock screen or iPhone 5s lock screen.
How to use:
You have to enable lock screen in settings in this application and you will see a new and beautiful interface of your lock screen. Access will be granted when you enter right password or passcode, you will not be able to unlock if you enter wrong password.
Do not worry, if you happen to forgot password, just press home screen and your screen will be unlocked.
Many custom wallpapers to choose from, also real time date and clock is visible which gives a realistic look.
This application is not for security purposes and is totally harmless.
Download and Enjoy.