Last year I had written about TuxPaint – a painting and colouring program for Kids used by son in his kinder garden days. In my son’s school (First Standard) last academic year they introduced him to a new program. And that program is “Drawing For Children” written by Mark Overmars and it is free. It seems to be very capable for growing kids to show their creativity.
Look at the below screenshot of what my son could do with this program in say 10-15 minutes!