There are a few ways to make your wallpaper’s more interesting in iOS 7. One is a dynamic, animated background: a nice idea, albeit one that uses a little extra juice.
More straightforward are the so-called ‘parallax’, little bit 3D-ish wallpapers where the background moves in conjunction with the way you tilt your phone/tablet using the motion sensors. This is the default for all ‘still’ backgrounds, but those not optimised for it can appear a little blurred due to scaling.
To avoid this you can create your own simply by adjusting the resolution of the wallpaper you use. You need to have 200 pixels on each side of the image to create the perfect parallax wallpaper. The correct resolutions are follows:
iPad 2 and iPad mini: 1,424 x 1,424
iPad 3 and iPad 4: 2,448 x 2,448
iPhone 4S: 1,360 x 1,040
iPhone 5: 1,536 x 1,040
The iPhone 4 doesn’t support parallax wallpapers.
You’ll need some sort of image processing app to do a/m image. Pixelmator is a good one, but also with the free, online image editor, Pixlr does the work. I use Photoshop, however use any other image app you want.