Block-based coding UI

Has there been any exploration of creating a block-based coding UI for education use?

My seven year old son has been playing on and had a lot of fun in particular with this Minecraft block-based coding lesson. It appears to be based on Snap.


He also really enjoys playing in Pi with me, but it takes a lot of hand-holding.

This is something I would potentially be interested in building. Maybe best done as a separate app which communicates with the Pi server?