There are 10 resources that I would recommend, feel free to add the public URL to you website or moodle page.
1) Sumo Paint - more sophisticated than paint which will keep you advanced user busy with layers and filters but easy enough to just create an image. You can save to the gallery, if you want to create an account, or download as an image if you don't.
|My favourite tools, symmetry and light effect filter!|
2) Tux Paint - this is what PWSD is supporting to replace KidPix. This is an offline program that needs to be installed. If you want it on your computer lab, just open a helpdesk ticket.
3) Pencil Maddness - This one is new to me, but I think it has loads of potential. Lots of cool tools and you can either create an account to save to the gallery, or just click on the JPG button when you are finished to download the image.
These are just three of the many tools listed, have fun exploring or set your student loose on them all!