Top 20 NuGet settings Packages

Easiest way you'll ever write settings for your app. This library is built to be modular and one-liner exploiting the powerful serialization capabilities of Json.NET out of the box without any mapping necessary to serialize nested custom objects, dictionaries and lists.
Feature flag utilities for .NET - based on etsy and reddit feature flag implementations.
CaveSystems Settings Bibliothek. This packages contains classes for ini(tialization file) based configurations.
ADN.AppSettingsCore is a cross-platform open-source library which provides application settings utilities to .NET Core developers
Some helpers for desktop application development with WinForms.
A strongly typed Settings/Configration management library
Package Description
Tired of copying data from .config/.settings files to objects and back again to make the data survive an application shutdown? Why not use this library, tack on a few attributes on your classes, and go look at funny kitteez on the internetz, visit a museum, or go have a chat with the sassy red head ...
A Settings library supporting multi-tier and data center environments.
Dynamic Settings is a .NET library that allows you to load application settings from a variety of sources including environment variables, ConfigurationManager, text files, YAML files, and Redis.
A way to write more configuration with less typing
GoogleAnalytics Plugin for Xamarin...
Cross Platform Geofencing Plugin for iOS, Android, and Windows
Electron Settings (electron-settings) binding library for Bridge.NET projects.
HolisticWare.Auth temporary replacement for Xamarin.Auth during porting/refactoring and testing