Supercraft is a tool that lets you build VR worlds within VR, and then publish and share via the Web! All running within the browser, from the creators of Supermedium and A-Frame. Read more at https://supermedium.com/blog/supercraft
Apps like Supercraft are great for the WebVR ecosystem! It feels good to use, I may use this instead of Google Blocks when making 3D models. There appears to be less z-fighting when objects are overlapped, which is important.
Short learning curve