What is the pricing structure of Google App Engine? Is it free?
GAE offers a usage-based plan to its users. There is also a Free Quota plan for a trial version that works to give a limited number of resources for applications. The Paid Plan works to bill the users for the product they use for the time frame that they use it. Two pricing models cater to users' needs - a Standard environment and a Flexible Environment. For more, you could also refer to the App Engine Pricing Page.