Lock screen widgets were first introduced to Android last November with Android 4.2 Jelly Bean, but in Google’s latest KitKat release, they’re disabled by default. But don’t worry — they haven’t been killed off altogether; you just need to enable them again if you want to use them.
Open up the Settings app and tap ‘Security’
Tap ‘Enable Widgets’
Go to your lock screen, then swipe over to the left and tap the plus symbol
Pick the widget you’d like to add to your lock screen