Google App Engine is a platform as a service (PaaS) cloud computing platform for developing and hosting web applications in Google-managed data centers. Applications are sandboxed and run across multiple servers.

There are a lot of cloud services available on Google AppEngine. But here, I will concentrate more into free features/services offered on Google AppEngine. Application Hosting (Without Databases) are free on Google AppEngine. For that you just need a google account. Setting up billings are not mandatory for that.

Here step-by step I will discuss how to create and deploy a sample application on Google AppEngine. These server side script are allowed on Google AppEngine – Python, PHP, Go, Java

Prerequisites:

1. A Google Account
2. Google AppEngine SDK need to be installed. For download and further set-up details, refer this URL: https://cloud.google.com/appengine/downloads
3. IDE for Application Development

Creating an instance of Application project on cloud

1. Login to Google AppEngine on this URL: https://console.developers.google.com
2. Click on Select a project >> Create a project
   
3. Provide a valid name to your App, and Create.
   

Creating an Application on local machine

1. Open Google AppEngine Launcher
2. Go to File >> Add new application
3. Select and fill applicable fields.
   
4. Click on Create
5. Open the created project with an IDE and code your application.

Deploying Application to cloud

1. Re-Configure your app.yaml file if any additional components added to your project.
   Ref: https://cloud.google.com/appengine/docs/python/config/appconfig
2. Make sure that Application name provided in app.yaml (in lower case) is exactly the same which you have created on cloud
3. Save the project
4. Add your project in Googe AppEngine Launcher if it not added/listed there
5. Select your project
6. Click on Deploy button
7. Provide authentication details of google account if prompted

Browsing your Application

1. Application will be available on application-name.appspot.com  ex- brappengine.appspot.com 
2. Here is a live responsive app hosted on Google AppEngine: https://brstatic.appspot.com