This repository has been archived and is no longer in use.
The Blockly Factory can be used here:
https://blockly-demo.appspot.com/static/demos/blockfactory/index.html
The documentation for making blocks may be found here:
https://developers.google.com/blockly/guides/create-custom-blocks/blockly-developer-tools
The source code for the Blockly Factory may be found here:
https://github.com/google/blockly/tree/master/demos/blockfactory