Limbo.Umbraco.Fetch is a package for Umbraco 9 for downloaded external files to disk to be used in your Umbraco installation.
For instance the package can be used to download the RSS feed of my blog to disk, which can then be used to display my recent blog posts on a website.
Install for Umbraco 9 via NuGet:
dotnet add package Limbo.Umbraco.Fetch --version 1.0.0-alpha001
Read more on GitHub.com