App locker, AppLock

to use you need to enable the feature that allows applications to access the system
App Locker can protect your privacy and private apps.
App Locker can lock your private apps (like SMS, Contacts, Gmail, Facebook, Twitter etc, Gmail, Email...)
and system apps (Like Settings, Calls etc.) and protecting your privacy.
With App Locker:
Secret question with multiple choice
Function when the forgotten password retrieval
You never worry about a friend borrow your phone to play games again!
You never worry about a workmates get your phone to have a look again!
You never worry about private data in some apps may be read by someone again!
You never worry about your kids may changing phone's Settings, paying games, messing up it again!

Features:
*Free.
*Support pattern unlock and password unlock.
*Lock 3rd party apps and system apps.
*Clean interface and easy to use.