A free app for Android, by Gamenjoy.

DARK WALLPAPER & LOCKSCREEN is an application for those who fancy customizing their phones without looking for wallpapers online. This lock screen and wallpaper does not easily drain your battery when using and it is also beneficial for you because it prevents your eyes from getting dry or strained due to its brightness. 

Moreover, you can choose various images as your lock screen or home screen for your phone. It is also awesome because you can download this game without any charges and taking so much space on your phone.