We use the Gravity Forms plugin for the Richard theme demo.
We have long used Gravity Forms on all of our development projects as well as with our own in-house and personal sites so we can recommend it whole heartedly.
That said, Gravity Forms is optional and not required for Richard to function. You are welcome to use whichever form plugin/solution you prefer on your site, or none at all.
If you are unfamiliar working with Gravity Forms we strongly recommend you invest a little time reading through their extensive plugin documentation. Gravity Forms is an incredibly powerful plugin with a vast array of addons available to extend the impressive core features of the plugin.
Here’s how to configure your Contact Us page like our theme demo once you have created your form and added your form fields.
Here is the exact markup we have in the main content area for the demo Contact Us page. We’ve placed it in a Gist because our forum software has a tendency to garble code from time to time.