Hey Erica!
Thanks for reaching out.
Site responsiveness is not actually dictated by our plugins at all—the degree to which a given page on your site is responsive is almost entirely dictated by the theme of the site, not the plugins.
To see an example of a responsive theme, and how our plugins play along with it, we indeed do have a demo site here which should be helpful → wpshindig.com/events
Check out that demo site in different browser sizes and on different devices, and you should be able to get a pretty good sense of how our plugin’s calendar views adapt responsively.
If you have any more specific questions or things I can try to help with here, let me know! 😀
— George