How do I point to a custom domain for free on Heroku?

When I go to the Heroku dashboard it clearly says:

http://dl.dropbox.com/u/30200856/Screen%20shot%202013-02-13%20at%203.20.03%20PM.png<br> "Free: Heroku branded domain" "Basic ($18 per month): custom domain"

After extensive searching on google I found others talking about how you can point to a custom domain for free:

1. http://jayzawrotny.com/blog/host-your-app-for-free-with-heroku
2. https://stackoverflow.com/questions/859516/do-you-use-heroku-to-write-ruby-on-rails-app
3. http://ididitmyway.herokuapp.com/past/2010/8/3/custom_domain_names_on_heroku_/<br>
4. https://stackoverflow.com/questions/7097108/should-i-deploy-my-ruby-on-rails-application-on-heroku
5. https://stackoverflow.com/questions/4536326/heroku-free-account-limited

I followed instructions as found on google to type in my console

heroku addons:add custom_domains 

but it said "App not found"

Did Heroku become un-free a while ago? What is necessary to have a custom domain for free?

>(1) How do I point to a custom domain for free on Heroku?

The Zeringo DNS addon has a Basic tier, which is free. This provides you with 1 domain per app, 10 host records, and 50,00 queries per month.

>(2) I .. typed "heroku addons:add custom_domains" in my console but it said "App not found"

The Heroku Addons Catalog stores details of most Heroku addons. The Custom Domains add-on entry reads: The Custom Domains add-on is now a standard platform feature.

It looks like the 'custom domains' add-on has been discontinued and merged. This could explain the 'App Not Found' error.

>(3) Did Heroku [custom domains] become un-free?

The Dev Center Article discusses setting up a custom domain by working with your DNS provider. This likely costs whatever your provider charges, which has nothing to do with Heroku, but might not have been explicitly mentioned in blog articles.