Kids are free to download the art and templates provided they only use them at home or school. I love Katie's video on helping kids learn to see so they can draw even better. I also love the variety of templates - not your standard three boxes, but funky, attractive, and bursting with zing! Here's a sample template below, and you can see Katie's artwork above.
Katie has some cute literacy-based worksheets on her main website, too, so be sure to check it out. Hint: look under Kids!
If you're interested in creating stories online with your kids, you'll find some more suggestions in my post: Sharing Stories Using Online Editors.