Exporting a region to Drive with an Earth Engine App?

I found an example using Google App Engine w/ Earth Engine’s backend to draw a region on a map and export that region’s information to your Google Drive. If you open the link, the example I am referring to is at the bottom of the page (it is called "export-to-drive").

https://developers.google.com/earth-engine/guides/app_engine_examples

I just wanted to know if this is possible with an Earth Engine App? Drawing a polygon or giving the user the ability to upload their own shapefile would be nice to know.