With FaBActivator you will finally have an easy way to protect your device as you want!
Go in Settings.app, choose you protection layout and respring. After respring you can use your device normally but when you want you can active your protection quickly via Activator or FaBActivator icon on your Home.
From FaBactivator panel in preferences you can choose if protect all Home Icons or some of them, same for Switcher icons (naturally you can choose which apps lock), disable NotificationCenter, disable PowerDown, disable Reboot, disable Home Button and, only for iPhones, disable Volume Buttons.
Also you can set the password you want, only on iPhones Enable the PIN Keyboard ( so, if you set a numeric password, you will be able to Enable/Disable protection faster), Enable sound when protection is activated/deactivated, show a banner when protection is activated/deactivated ( if not enabled this FaBActivator will show you a popup), hide Icon from Home and set an Activator action to Enable/Disable the protection.