BuiltWith for Zendesk
If you use Zendesk for your support and sales tickets then the BuiltWith Zendesk App is a must have. It basically highlights the technology spend and premium technologies that the customer of the ticket you are looking at has.
It also costs nothing - you're welcome.
Install it via - https://www.zendesk.com/au/marketplace/apps/support/803760/builtwith/