I don't use Godot, but I ventured to try this (and maybe finally check out the engine), and I really like the concept. 

When I tried to use it, though, I ran into a bunch of issues: The startup screen didn't detect when I copy-pasted an install location, so I had to navigate to it manually. The settings screen seemed to reset its options every time I visited (and exiting settings didn't show the "Latest Download" section anymore). Also, pressing Download either did nothing or had an error - so I wasn't able to actually try it haha. I tried running with Administrator permissions, and it wouldn't download. I then tried creating another folder in my Downloads folder, just to test it, but I wasn't able to change my previous "installation location" in the app.

However, I think this has a ton of promise, and I'm not fully sure what issues may be on my side or with the app. If Godot doesn't already have something like this, then based on the screenshots, it could be an incredibly useful utility, similar to Unity Hub or the Epic Launcher. Sorry that this is the best feedback I could give, but the app really seemed to hate my computer.