Maybe priced too high, not updated in a while
"Material Maker is a procedural materials authoring and 3D model painting tool, based on the Godot Engine. Materials and brushes are defined as graphs where nodes create or transform textures, and can be exported for the Godot, Unity and Unreal game engines. ... Material Maker can be used to create several types of materials, and new custom material types, as well as new export targets for existing materials, can be added if needed."
"MAST (Modular Asset Staging Tool) is a custom editor for Unity, primarily intended for staging 3D modular assets, and is very useful for making scenes and levels that are based off of a grid. Instead of having to drag a prefab into the inspector, then manually move, rotate and flip it, MAST provides a simple interface that lets you do all the above before ever placing the item in your scene."
"SuperTiled2Unity is a collection of C# Unity scripts that can automatically import Tile Map Editor files directly into your Unity projects." (How does this compare to Kitty?)
"The Twine to Ren'Py tool allows you to write a simple Ren'Py game but with the visual outlining of writing in Twine. Convert a Twine html file into rpy files for your Ren'Py game project."
"Create your own Point and Click adventure games without writing a single line of code!"
"Build games in Blender! Armory is a game engine with full Blender integration, turning it into a complete game development tool."
"The resources found in my 2D rule tile/tilemap tutorial can be downloaded here.
Download contains the complete 2D platformer spritesheet with tiles for every possible platform scenario. "
"2DLightShader is the definitve and easier solution to bring light and color to your 2D Unity's creations. You can use it into sprites, tilemaps or even particles, and even being a 2D object, the light will behave as if it were 3D object, without any 2D light package needed and using the generic Unity lights."
TileMap Auto Rule is a little tool to speed up your workflow if importing new Tilemap using Rule Tile in Unity.
You just have to follow the template included to create a new one.