I started working on a tool this week, and when I saw your post I figured I might as well submit it to this jam for extra motivation :). I ported over an Entity/Component framework for LibGDX I wrote during LD to my utils library, and I'm now adding a editor to this. The goal is to make something Unity-like, where you can edit abritrary field of the game objects. I'll try to make is as user friendly as possible, so that maybe other people start using my library.