Scratch is fantastic. There are also a number of similar (block-based) tools that let you create your own custom blocks and see the code behind them - e.g. Blo

Scratch is fantastic. There are also a number of similar (block-based) tools that let you create your own custom blocks and see the code behind them - e.g. Blockly (https://developers.google.com/blockly https://developers.google.com/blockly)