Great work here. After installing and following the well articulated instructions, the app worked as intended. However, in further testing, it worked on one machine, not another, in one browser not another and one username not another. It was very confusing and I spent hours in trial and error. I finally figured out the issue.
When a facebook user has the "access via https" setting activated, the page did not display in facebook. I had set the app up in facebook with a "secure canvas url" but that hasn't seemed to resolve the issue.
This plugin has so much promise, but I know many people who use that https setting. Any guidance here?
Thank you so much.