What are some alternatives?
When comparing Tilt Brush by Google and Oculus Medium, you can also consider the following products
Snap Art - Snap's augmented reality platform
MasterpieceVR - Powerful VR sculpting & painting tool
SprayPrinter - Convert digital designs into wall art from your smartphone
A-Painter - Paint in VR in your Browser
VR Sketch - A tool for designers to draw inside virtual reality
Blocks by Google - Easily create 3D objects in VR