******* Once you will download a photo using app. It will be available your phone's Gallery.
Now you can use it offline and can share it on Whatsapp and on social media like facebook,
Google Plus etc.********

Using app is really simple.
>>> Open the app
>>> Click your favorite photo
>>> Click the "Set Wallpaper" in menu after the download is complete.

99% of mobile devices compatible HD wallpapers.
Screen resolution, and (including tablets) devices all support.