if you have some nice pictures, you want to set it as wallpaper, but its width-height scale is not fit your device's screen, eg. screen of 320*480 needs wallpaper 640*480, 480*854 needs 960*854 etc.
my app can help you to set any pictures as wallpaper, not only one picture, but more. you can locate it in any positions.
ok, I know my English is poor, just download and use it.