Calendly is an app for scheduling appointments, meetings, and events.
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.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Open Graph is a protocol that is used to integrate any web page into the social graph.
OptiMonk is an on-site message toolkit used to improve conversions using action-based popups ad bars.
WhatsApp Business is a free to download app available on Android and iPhone using which businesses can connect with their customers.