Interaction Design patterns are solutions to commonly faced design problems. Proto.io offers you a number of these patterns, as complex UI components that you can add to your project and customize, saving you a lot of time.
This video explains how to use the "Scrolling feed" pattern. It adds a scrollable container to your canvas. You have the option to choose the number of placeholders and the scroll direction before adding. Once you have it on your canvas, you can double click to edit the container and customize it by adding your content.