Xam.Plugins.ImageCropper is a useful image cropping and rotating library for Xamarin.iOS and Xamarin.Android
Please follow the Sample solution in repo to use them in Xamarin.Forms.
You can build these binding libraries by your self.
For iOS, run make in iOS/extern, then build iOS project.
For Android, download the lastest .aar and import the package into Android project, make sure you have installed JDK 1.8 and Android SDK 25.
Android library from : https://github.com/ArthurHub/Android-Image-Cropper
Update to 2.4.6
iOS library from : https://github.com/TimOliver/TOCropViewController
Update to 5665779