Try it online or download the app. You can also go Pro. Visit Sumo Paint site for details:
Sumo Paint Program: http://www.sumopaint.com

Please wait for the program to load. For Full screen go to: View --> Screen Mode ---> Full Screen
Sumo Paint is an amazing program with many features. It can be used in the classroom to teach many concepts in art, math, etc.
Sumo Paint: Web-based Paint Program