PlastiSketch VS Zero Brush

Union Bytes Painter - 2D sprite and low res texturing tool for editing with color, normal, height, roughness, and metallic maps.

Blender - Blender is the open source, cross platform suite of tools for 3D creation.

Quixel Mixer - Mixer is a PBR creation suite that uses brushes and non-destructive layering to generate all types of maps.

Mudbox - Autodesk Mudbox digital sculpting and texture painting software provides 3D artists with an intuitive toolset for creating highly detailed 3D geometry and textures.

3D-Coat - 3D-Coat is the one application that has all the tools you need to take your 3D idea from a block of digital clay all the way to a production ready, fully textured organic or hard surface model.

TrueSculpt - Model a virtual clay ball by pushing or pulling it with your fingers.