We're pleased to see that ScratchJr is getting closer to availability. We're big fans of the Scratch graphical programming language for bigger kids. ScratchJr provides an experience for younger kids aged around 5 to 7.
There's currently a ScratchJr Kickstarter project running to get support for the completion and release of ScratchJr for the iPad in 2014.
My kids are in the age range for ScratchJr but they're both using Scratch. I think my 5 year old will love ScratchJr though, he needs quite a bit of help with Scratch and would enjoy being more independent.
There are some barriers to younger kids getting started with Scratch. They might not be able to read well, and Scratch uses a grid with negative numbers, and angles of a circle to turn. But younger kids do have the logical thinking skills to do some coding.
ScratchJr builds on the skills younger kids do have and allows them to build animations and simple games.
ScratchJr is initially planned for the iPad. Hopefully other platforms will follow as a lot of schools and homes don't have access to an iPad but so have PCs and Android tablets.