When you set a wallpaper on your iPhone, you will be missing an option to edit the wallpaper according to the iPhone settings. The iPhone allows you to Zoom in or out, but it really misses some cool features like preview, rotate etc.
Wallpaper Fix is a new application which is 99 cents (but free as of now), will allow you to Rotate, scale, zoom, crop, edit and position your photos for your Screen and Lock screen wallpapers.
This application also allows you to preview the wallpaper (both lock screen and home screen) inside the application itself. Once you are satisfied with the wallpaper, you can click save. Then select it from settings to set it as you wallpaper.
Requires iOS 7.0 or later.
Compatible with iPhone, iPad, and iPod touch.
This app is optimized for iPhone 5.
I have tested it on my iPhone 4 and it works just fine.
Get it from iTunes
[Via Redmond Pie]