GIMP for Kids
My daughter likes to draw on the computer. I don't remember exactly how it started, but she draws in GIMP using my Genius pen tablet, on my secondary monitor. I used to have Linux running in a VirtualBox with GIMP running on my second monitor for her, but VB doesn't completely work in Windows 10 yet. A while back I tried running GIMP on one of my Raspberry Pi's but it was just too sluggish to be useful, frustratingly slow for a (then) 3-year-old. It runs much better on a Raspberry Pi 2. It still lags if she goes crazy with a big brush, but it works.