With this app everyone can also share his own creation; in fact we made a “Users" category where you can upload all the wallpapers you want with proper credits.
If you find a wallpaper (yes, all the credits are given) and you don't want it in the app please contact us.
We also created a website and you can access to it via mobile, via desktop or whichever device.
The app is open source so if you want to use the code to make a your own wallpaper app or you want to improve the project, you can simply go to the Github page and download the code.
App page: https://play.google.com/store/apps/details?id=com.lob.mwhd
Google+ Community: http://tinyurl.com/MaterialWallsHD