GitHub repository (source: https://rstudio.github.io/shiny/tutorial/#deployment-local)
If your project is stored in a git repository on GitHub, then others can download and run your app directly. An example repository is at https://github.com/rstudio/shiny_example. The following command will download and run the application:
shiny::runGitHub('shiny_example', 'rstudio')
In this example, the GitHub account is ‘rstudio’ and the repository is ‘shiny_example’; you will need to replace them with your account and repository name.
Pros
Source code is easily visible by recipient (if desired)
Easy to run (for R users)
Very easy to update if you already use GitHub for your project
Git-savvy users can clone and fork your repository
Cons
Developer must know how to use git and GitHub
Code is hosted by a third-party server