13.1 Introduction

• Shiny is a web application framework for R that enables us to build interactive web applications.

• Shiny apps are useful to communicate information as interactive data explorations instead of static documents.

• A Shiny app is composed of a user interface ui which controls the layout and appearance of the app, and a server() function which contains the instructions to build the objects displayed in the user interface.

• Shiny apps permit user interaction by means of a functionality called reactivity.

• In this way, elements in the app are updated whenever users modify some options. This permits a better exploration of the data and greatly facilitates communication with other researchers and stakeholders.

• To create Shiny apps, there is no web development experience required, although greater flexibility and customization can be achieved by using HTML, CSS or JavaScript.