You can either use the master branch with embedded Shiny apps. Then you have to use a Shiny server to view the presentation, e.g. in RStudio, run rmarkdown::run() or simly click on the "Run Presentation" button.

Or you can use the static branch, where the HTML file can be viewed with any browser. The Shiny apps have been replaced with animated GIF images that give an idea of the interactivity.