Top 20 NuGet Xamarin Packages

Cross Platform Mobile Development
To easy use mvvm in android,ios,uwp,wpf ect.
LightMock is a simple mocking library that can be used on platforms that does not allow dynamic code generation.
Android platform specific code
Extended and improved controls for Xamarin Forms
This library works like Objective-C and Swift NSNotificationCenter
CrossFileHelper helps you to jump start to do file related functions in a quick and easy way.
A small library to quickly and easily add infinite/endless scrolling support to any Xamarin.Forms ListView.
This Package is designed and written for open source usage whenever the QA engineer wants to test on any browser that is supported by seleniumHQ libraries.
Xamarin.Android bindings for Crisp SDK
MagTek mtscra.a bindings for Xamarin.Android
Xamarin Yandex Maps Android
Xamarin Helper Library to get the name of the current Android device.
AndHUD is a Progress / HUD library for Android which allows you to easily add amazing HUDs to your app!
The Red5 Pro Second Screen SDKs are a combination of native libraries and frameworks (a.k.a., Client SDKs) and HTML5 libraries (a.k.a., Host SDKs). Red5 Pro Second Screen allows a Host (e.g., an HTML5-supported browser) to connect to and drive the content of Clients (e.g., Native Applications).
Tabbed pager for iOS
Custom UIViewController that slides scrollable content up from bottom of screen which covers the main content view on screen.
A programmatic approach to building Xamarin.iOS UIs with stack views (horizontal and vertical) and animations during segue transitions
MagTek mtscra.a bindings for Xamarin.iOS
An iOS tutorial and associated library for keeping an UICollectionView in sync with a dynamic SQL data model.