I picked up a chromebook for my daughter the other day and was looking for web based programming apps. I came across "Run Marco", built using Blockly, which is fairly basic at this point but seems to be under active development.

https://www.allcancode.com/runmarco

(in the CWS https://chrome.google.com/webstore/detail/run-marco/objdeaib... )

Worth checking out if you have a child and you're looking for a lightweight web based programming intro.