I got my kids the Kano computer kit based on the Raspberry Pi 2 for Christmas. It is running a custom operating system from Kano, so I thought I would need to load Raspian on a separate memory card, to try out Xojo apps. To my surprise, I was able to load a Xojo built app directly on the Kano.
The Kano kit has kids instructions for assembling the computer. Everything needed is included. The kids put the pi in a case, insert the memory card, attach wifi and bluetooth dongles, attach a speaker using the gpio pins and headphone jack. It gives the kids a great sense of accomplishment, that they have built their own computer. The kit has apps built in geared toward teaching kids to code.
This kit goes even further that not only can my kids use the coding apps built in, but we can make apps in Xojo to run to the kit.