app.rb

module App

  class Root
    def call env
      [ 200, { 'Content-Type' => 'text/html' }, ["root page"] ]
    end
  end

  class Info

    def call env
      [ 200, { 'Content-Type' => 'text/html' }, ["info page"] ]
    end

  end

end

config.ru

require './app'

map '/' do
  run App::Root.new
end

map '/info' do
  run App::Info.new
end