picoCAD
A tiny modeller for tiny models
Sprytile
A Blender add-on for building tile based low-poly scenes with paint/map editor like tools
RPG Paper Maker
A 2.5D game making engine free for non commercial use!
picoCAD 2
Low-poly modelling, texturing, and animation.
Puck's Pixelizer
An all in one tool that helps you pixelate and see real time changes on your models.
MESH EDIT
A Unity extension that lets you create and texture models from scratch!
Planet Painter
Spherical terrain editor
Texture Grub - Texture creation software
Easily create and edit textures for game dev and modeling.
Stereo Imagination
Python programming toolkit for generating and manipulating 3D geometry from code
Whisk
Not quite a Blender
Assemblr Studio - Build AR in Bigger Canvas
Quickly create Augmented Reality experiences with the power and flexibility of your desktop
Elyoko
3d game engine for code lyoko world
PELOGEN (PICO-8 3D modeling tool)
Tinypolygon for PICO-8
PELOGEN2 (3D modeling tool for PICO-8)
Tiny polygons for PICO-8 again!
Stylized Rock Generator
Procedural Ghibly-style rocks in Blender 2.4 and newer