From the site description
Easily draw on maps and then share them with friends, completely for Free! Simple enough to be used by children, but powerful enough to be used by GIS professionals – Scribble Maps is the easiest way to draw and share maps with friends.
I have been using this site for creating custom maps for our home tour videos. It is a great way to add your own information to a map and share it with your social networks. You can also download your map for use in other materials.
Useful website for creating custom Google maps