You can now use your proprietary R packages in your shinyapps.io environment. To do so, your package does need to be hosted on in a private github repository (public github repositories have always been supported).
To enable the feature you need to follow these simple steps
Log into the shinyapps.io dashboard. Click on Account, and then the Profile tabs.
Under the authentication menu, you will see a setting to “Link” this account with your Github Authentication.
Click on the Link Account, and authenticate using your Github authentication information.
The previous step has set it up so you can now authenticate to shinyapps.io using your github authentication credentials. The final step is to provide shinyapps.io with the authority to read from your repository so that it can check out the code. Click on the “Private Repository Access” checkbox.
You will be presented with a page that asks you to “authorize the application”.
Clicking on “Authorize Application” will enable shinyapps.io to build your application. The resulting page should look like this: