Wallpaper Pro is a nice app that has large variety of 4k wallpapers and live wallpapers.If you are not satisfied with your system homescreen backgroundtry it.

-10000+ wallpapersall in 4k and HD quality.
-Live wallpaper:making your homescreen dynamic.
-3D wallpaper:set wallpaper in 3D effect
-Varieties:Popular/Nature/Winter/Beauty/Cartoon/Car….
-Phone Transparent:transparent effect backgroundmaking your phone pretty cool
-Wallpaper Auto Change:change your phone background automatically
-Call Flash:you can customize your caller screen with our themes