This is the folder that holds source code for apps you are deploying to Heroku using Dropbox Sync. There is a subfolder for each Heroku app on your account that is configured to use Dropbox Sync.
Don't create additional folders here. To enable Dropbox Sync with a Heroku app, access the Heroku Dashboard and follow the Dropbox instructions on the app's "Code" tab.
For details, please refer to the Dropbox Sync documentation: https://devcenter.heroku.com/articles/dropbox-sync
Feel free to delete this file.