Brainrush have added another quiz template feature – HotSpot.
Upload an image and label the key features through a variety of hotspot tools (circle, square and polygon)
You can alter the hotspot colour (not invisible border though) and add in a sound file for added interaction.
Once you publish you cannot edit sadly.
Pretty impressive for free!
http://www.brainrush.com/lesson/digestive-system-7 is a very poor attempt