This tool allows you to select out of 2 templates and 4 different characters among a specific topic. I don't know exactly how it works because I haven't got the time to do many things but I think it is another nice alternative.
It also has a paid version from which you can get much more things to do, but I think that as it is could be easily implemented with a course of kids, adolescents, and why not, adults... here you have the topics you could be using: http://goanimate.com/videomaker/quickvideo.
And for you to see what you can do, I've created my own video!

http://goanimate.com/videos/0TjMA7MIN8iM/1 Hope you enjoy it!