ScreenBlur allows you to lock and hide your desktop, easily unlocking with a password. Hide visible windows, icons, gadgets and taskbar, also has auto lock, hotkeys, mute sound, customizable lock screen, and more.
Version History for ScreenBlur: https://drive.google.com/file/d/0B2QSXjtE26ORNGdMOWRSVE5mYTA/view?pli=1