cdnjs is a free distributed JS library delivery service.
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.
Histats is a simple website visitor analysis and tracking tool.
Linkedin Sign-In is an authentication system that reduces the burden of login for users, by enabling them to sign in with their Linkedin account.
Open Graph is a protocol that is used to integrate any web page into the social graph.
WhatsApp Business is a free to download app available on Android and iPhone using which businesses can connect with their customers.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.