Defnite is currently in very early stages, but is developing well. If you want to take part in the journey, visit it on itch.io.
Finder for Game Creator is a module for Game Creator and allows you to find and edit all Game Creator components and scriptable objects in centralized Editor windows.
Skills is a module for Game Creator and allows you to add skills to your game.
For more extensions, look here.
I am making guides for Game Creator and its API. Learn more here.