In this app first will be a display of Main Screen image and then when you tap to that screen it will navigate to inner screen where custom live wallpaper seen, you can pick any images from your gallery and see the preview if you like than tapb on set as wallpaper, It will automatically set as your wallpaper.
How To Set Live Wallpaper:
Step 1:long press on the home screen
Step 3:Live wallpapers
Step 4:Select set Wallpaper
And Now See Live Wallpaper in Your Home Screen....