HUD Design Tool

Currently I’m working on HUD. My first approach was straightforward: hard-coded elements. As you can imagine not very flexible. So I’ve moved it to JSON + content pipeline extension. Much better but without WYSWIG I have to run game to check if everything is ok.

So I thought that maybe someone already created HUD Design Tool. I’ve checked google and nothing. It looks like all tools to create HUD are embedded in game engines(for example Unity). I need something that allow to create HUD with static elements and basic anchoring. Of course result of the design would be metadata file. So long story short I need something like Tiled but for HUD.

Can someone recommend something?