Scratch is a free to use online programming environment which uses drag and drop blocks to write code. Its very effective at showing the kids programming logic as well as a fun way to flesh out their ideas. Here is an example by a student at the SML college in Fishersgate, Sussex.
CAT FAT SIMULATOR by Alex @ SML College
The student is age 10 and shows remarkable understanding of programming logic as well as game design, scripting and application user retention. This in my opinion is down to the ease of use of the Scratch system and the way in which it demonstrates core principles extremely well to the student.