Calendly is an app for scheduling appointments, meetings, and events.
Cloudflare is a web-infrastructure and website-security company, providing content-delivery-network services, DDoS mitigation, Internet security, and distributed domain-name-server services.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Vimeo is a video hosting, sharing and services platform. Vimeo operation an ad-free basis by providing subscription plans.