Windows phone 8.1, library/project with interface for crop an image

I am looking for a library/package/project for cropping images, but in what I am most interested is not in the part of programatically crop the image, I need a library for cropping an image with an user interface, wich is the most complicated part.

Do you know any? I have been looking for throught google, nugget gallery...

I need it for Windows Phone 8.1 XAML (not silverlight)

Thank you.