I've been trying to get my kids interested in coding. I found this nice game called Lightbot, in which one writes simple programs that control the discrete movements of a bot. It's very intuitive and in just one morning my kids learned quite a bit about the idea of an algorithm and the notion of a subroutine or loop. Some of the problems (e.g., involving nested loops) are challenging.
Browser (Flash?) version.
There are Android and iOS versions as well.
Other coding for kids recommendations?