Reviewed in Apps you wont uninstall
If you know, android makes it compulsory to have one widget on your lockscreen. If you don't use a widget, android replaces the blank area with clock. So what happens if you want a blank lockscreen ? You need a blank widget. That acts like a widget so that android does not put a clock on blank lockscreen and at the same time you don't see anything in this widget..
This is a blank, transparent lockscreen or homescreen widget without any functionality. Use it to fill up pages on your lockscreen (prior to Android 5) or homescreen. A very simple widget that doesn't use up unnecessary resources. To use this, just add 'Blank' from the new widget dialog.
Google REMOVED lockscreen widgets ever since Android 5.0, so this widget only works on the homescreen before that and on specific phones.