What are some alternatives?
When comparing Kingspray Graffiti and Quill by Story Studio, you can also consider the following products
A-Painter - Paint in VR in your Browser
MasterpieceVR - Powerful VR sculpting & painting tool
Oculus Medium - Sculpt, model and paint in virtual reality on a 3D canvas.
Tilt Brush by Google - Paint in spaces around you with Virtual Reality
Blocks - Empowering designers to build great websites without writing a line of code. For web and OS X.
VR Sketch - A tool for designers to draw inside virtual reality