PluginsForXamarin 

Check to see if your users have granted or denied permissions for common permission groups on iOS and Android. Additionally, you can request permissions with a simple cross-platform async/awaitified API.

Settings Plugin for Xamarin and Windows provides a consistent, cross platform settings/preferences plugin. This makes it easier to create cross-platform .NET apps and have cross platform settings. Manage and use all settings from one PCL/NetStandard library and save natively on each... More information

Easly access geolocation across Xamarin.iOS, Xamarin.Android, and Windows.

Get network connectivity information such as network type, speeds, and if connection is available. Additional functionality includes the ability to ping a specific host and port number. Ensure you have proper permissions set by reading the README.

Provides a simple solution for getting access to the current Activity of the application when developing a Plugin for Xamarin. This will lay down a base "application" class for developers in their Android application with boilerplate code to get them started.

Xamarin and Windows plugin to perform text to speech functionality. Adjustable pitch, speak rate, locale, and more.

Take or pick photos and videos from a cross platform API.

Receive information about the device that you are using. Properties such as Model, Operating System, Version, Id, and even the ability to generate a unique Id for your application based off of these properties.

Share Plugin for Xamarin and Windows to share text, link, copy text to clipboard, or open a browser.

Open external maps to navigate to a specific geolocation or address. Option to launch with navigation option on iOS as well.

Xamarin and Windows plugin to vibrate your devices. Read the full documenation on the projects page.

Subscribe to battery change notifications across iOS, Android, Windows Phone, and Windows from a single API. Ability to gather current battery level, charging status, and charging type.