Another direction the author could take with this: a CAD app. Specifically, because TinkerCAD is shutting down, 3D printing community desperately needs a new CAD tool usable by 10-years-old kids. There's a huge opportunity there.
TinkerCAD was very popular with 3D printing people, because it was stupidly simple and easy to learn, while still being a very functional CAD tool.
I worked at Tinkercad for about 6 months last year (mostly on the WebGL-based editor, but the engineering team was only 5 people so there was lots of other stuff to do as well). It's an awesome product; I'm surprised and sad to see it closing down, but at the same time I can understand why they decided to pivot the core tech into a new company.
Basically Tinkercad had two unique advantages: a world-class massively parallel solid geometry kernel, and a 3D design UI that made ease of use first priority. Tinkercad emphasized the latter in their product image, but it became somewhat pigeonholed as a "children's CAD", which made it difficult to switch the same product into a pro gear. They've now made the decision to pursue the revenue potential of the pro market, and that requires a new product image.
If someone wants to jump onto the opportunity of building a Tinkercad replacement, I know a few things about this space and am available for hire... ;)
It's going through a major transition at the moment (http://shapesmith.net/2013/03/06/ProgressUpdate.html), and not necessarily kid-friendly, but it's open source so someone could create a kid-friendly interface
I am so incredibly sad TinkerCAD is closing. It has been my introduction to CAD and it has been phenomenally useful. I'm trying out Autodesk Inventor Fusion, but it's so much more complex, so it'll take a while before I feel comfortable in that.
TinkerCAD was very popular with 3D printing people, because it was stupidly simple and easy to learn, while still being a very functional CAD tool.