The silent video without annotations thing is a bit strange, as somebody who has never used fitfrnd I'm not sure what I'm supposed to be looking at. Perhaps a simple Javascript slideshow widget with labels might work better? The pictures on fitfrnd.com are a lot more effective at illustrating the functionality of the app, though admittedly less information-dense than an animation or a video.

Edit: sorry, I just noticed technel made the same point below and saw your reply.