how do you configure tether for popups with Zurb Foundation for Apps?

Question

I'd like to use popup functionality from Zurb Foundation for Apps (Zurb's popup documentation) which uses Tether (Tether on GitHub). I've tried using the configuration as found on GitHub:

            new Tether({
                element: "yellowBox",
                target: "greenBox",
                attachment: 'bottom left',
                targetAttachment: 'top left'
            });

I'm running this in my Angular JS directive. However, I get a JavaScript error in tether.min.js (Error: t is null). That error message is not very helpful.

Zurb's documentation does not indicate how to configure popup. I want the popup to happen to the right of the element that was clicked to open the popup.

Thanks for your help.