Top 20 NuGet appsettings Packages

Toggle your features from app-settings in your application
This package contains utilities for logging and app setting. It includes versions for .NET Framework 4.0, 4.5, 4.5.1, and 4.5.2.
Allows you to work with complex configuration structures in your app.config or web.config files. Doing it the classic way with System.Configuration is difficult and error prone. JJ.Framework.Configuration makes it super easy.
Part of the MetaSaver framework that handles application configuration including a strongly types AppSettings
Automatically enables nesting of appsettings files in JetBrains Rider.
Configuration helper classes.
Configuration Reader for .NET Framework applications
Library to handle AppSettings and ConnectionStrings. Repository:
Extensions for Microsoft.Extensions.Configuration.Binder that simplifies the process of binding a configuration sub-section to a class, a little bit.
DevAttic ConfigCrypter Console is a dotnet tool used to encrypt and decrypt keys in configuration files.