cdnjs is a free distributed JS library delivery service.
Fly is a platform for running full stack apps and databases.
Google Analytics is a free web analytics service that tracks and reports website traffic.
Google Tag Manager is a tag management system (TMS) that allows you to quickly and easily update measurement codes and related code fragments collectively known as tags on your website or mobile app.
Ruby on Rails is a server-side web application framework written in Ruby under the MIT License.