Yes, but OP is wrong when he says that there is nothing to see. He just didn't take the time to even look. The source code of the underlying layout engine is published on GitHub: https://github.com/gss/engine
But that's not the commercial asset that "The Grid Co" is demonstrating. They are abstracting that underlying framework, to make a more usable asset to non-technical people, akin to a SquareSpace. The people who have bought into this notion (i.e. the "founding backers") have seen almost little to no substance to establish the latter. The argument is that they are essentially being tricked. The resulting question ("is it OK to start a company this way?") is probably much more ethical in nature than anything.