Simple Notification Service (SNS) is a real-time messaging service designed to allow applications to send alerts and messages to multiple receivers at the same time. Amazon has kindly provided a tab for us to manage our SNS subscriptions in the AWS Console, so we will be using this to manage our SNS service. Also, we will be using an external service called www.postbin.org, an excellent website used for visualising Web Hooks used by services such as SNS.
SNS works by providing a Topic, which can be Subscribed to by multiple subscribers using various technologies, such as e-mail and HTTP. By providing a single topic, one message, when posted, may be reliably delivered to multiple subscribers. An example of this is an alert, which may be posted by an application such as our Waaah sample application.