I have played around with both Forestry.io and the Netlify CMS as CMS providers for my static (hugo) site.

Both are great as free services. I like the Netlify CMS since II can self-host it in the site itself. It also allows a little more customization.

I could not get it to work as they prescribed though. Specifically with the directory structure:

/static
   | - admin
        | - index.html
        | - config.yml

instead I had to do this:

/static
   | - admin
   |    | - index.html
   | - config.yml

That got it working. In fact this post was written in Netlify CMS.