Working in an elementary school I've learned to appreciate applications that I can suggest for my students to use at home. These programs need to be safe, easy to use and have the ability to be integrated with the curriculum in multiple ways.
One of the programs that I'm using this year is Tux Paint. Tux Paint is a free drawing program that can be used by children preschool through sixth grade. Besides the fact that the program is free, I also like the fact that it is available for Mac, Linux and Windows and by following the easy to use directions I'm able to add custom stamps to help students with their projects.
We're presently using the program for students to create illustrations to go along with their fairy tail retells. It's easy for students to use, has been extremely stable and includes a number of features that high end children's drawing programs include.