Push Hook

model_application.rb

class Application < ActiveRecord::Base
  require 'httparty'
  ...

  def push_message(message)
    if self.post_url
      post(self.post_url, :body => message)
    end
  end
end

model_message.rb

class Message < ActiveRecord::Base

  belongs_to :user
  after_create :push_to_applications

private

  def push_to_applications
    user.applications.each do |app|
      app.push_message(self)
    end
  end
end