Wallpapers HD is a very useful app for finding the most beautiful HD wally and totally free. it contains a lot of categories :
abstract Wallpapers ,
animals Wallpapers ,
nature Wallpapers ,
dark&black Wallpapers
love Wallpapers ,
technology Wallpapers ,
cars Wallpapers ,
people Wallpapers ,
galaxy Wallpapers ,
sports Wallpapers ,
cities Wallpapers ,
and more.
you can gave many features browsing the app:
-save wallpaper
-share wallpaper
-set wallpaper to home screen
-set wallpaper to lock screen
-set wallpaper to both screens
and more.