Here it is. After almost three years, I present to you the wallpaper version of Friendship is Survival! Check out the original deviation below to read about the hypothetical Left 4 Dead game featuring these humanized ponies.
Available as for desktops, mobile phones and anything that you can crop it to. Just download the ZIP file to get both versions.
Works on 4:3 aspect ration, though some of the guns will be cropped out, but who uses 4:3 these days.
Suited for the most modern of phones with 1080p capabilities. There is enough blank space on the bottom for cropping. Most phones and tablets will allow you to crop the image yourself.