This video is showing you how to create App for SharePoint in Office 365. Most of the videos are showing how to create App for SharePoint without interacting with Office 365 SharePoint. In other word they are just a blank application. The application in this video is creating a List Item physically to Office 365 SharePoint Dev Site. I will write a blog on this as well.
To get the cer see this link https://chanmingman.wordpress.com/2015/07/11/create-high-trust-apps-for-sharepoint-2013/. .