Suppose you want to access some JSON data from a mobile app using Cordova. You have to bypass CORS restrictions in the web view, and to do that you have to provide some HTTP headers in your Django views.
Recently I had some fun with Heroku, the well known PaaS provider. I had a small personal Django project I use for invoicing that I ran locally with ./manage.py runserver when needed. That was a perfect candidate for the Heroku free plan because I need to access the app only occasionally.