Literally start from Scratch!
The group has started using Scratch to design their own application. The first one was an 'About Me' page where they chose to write code to say something about themselves. They also wrote code to make some action happen on the About Me page. eg. make the football roll from one side of the room to the other, make their cat purr a 'meow' sound.
The next session was devoted to making a dance party. The children came up with very interesting ideas and then showed the work to the rest of the class at the end of the session.