After updating Galaxy S2 to Jelly Bean, in some cases you can't set the wallpaper properly, because the area you can select of an image is limited! This area is square shaped and doesn't fit portrait images. You see much less of your image, and gets scaled and distorted.
This app fixes that problem, making possible to crop a bigger area of all images, preserving quality and resolution. Great for lock screen and the Touchwiz launcher without scrolling wallpaper.
This app comes as an option when you try to set a wallpaper.
The stock Gallery app is required.