How can I keep my Heroku application private?

My cheap solution has been implementing a before_filter to request an HTTP authentication before every action is executed.

This solution works well along other authentication layers – Devise or others.

USERS = { "user" => "secret" }

before_filter :authenticate

def authenticate
  authenticate_or_request_with_http_digest("Application") do |name|
    USERS[name]
  end
end

Whenever other peers land at yourdomain.heroku.com, they are asked for HTTP authentication, later for other authentication if in place.