Hello,
I can write for you a Xamarin iOS app (Visual Studio 2015 project) that will let you select an image, from the device image gallery or from the camera, and edit the image. You will be able to pan and crop the image.
I will write for you a complete example and I will also be available for chat if you will need help with understanding/using the code.
Thanks and let me know if you are interested,
Paul