I created this sample platform agnostic TOC screen for a mobile learning course: - If you are on a laptop or desktop, clicking an image on this screen, causes a transparent and overlapping layer to appear on top of that image. This layer displays the lesson name corresponding to that image, along with links to the topic names in that lesson - A similar effect is seen when the course is run on tabs or smartphones, with the triggering action of clicking being replaced by the tapping action for touch-screen devices