Class Dojo

http://www.classdojo.com/
https://play.google.com/store/apps/details?id=com.classdojo.student
http://education.fcps.org/trt/classdojo
http://betaclassroom.wordpress.com/class-dojo-review/
http://www.teachingsuperpower.com/2013/02/class-dojo-made-me-better-teacher.html