Really nice - really like it for just fiddling around with models.

One missing feature would be an "undo" function - I accidentally deleted a layer and couldn't find a way to undelete it?

Edit: just found an error when trying to actually train a network:

TypeError: Argument 1 of WebGL2RenderingContext.clientWaitSync is not an object.

This was doing a very simple MNIST->dense(200)->dense(1)->output model using Firefox 65