Does what it says. You can inspect the state in the Inspector tool on a locally running Angular project. It is not as convenient as other dev tools such as for Vue or React.

it app no run in firefox

First of all, I'm very thankful this exists. Now that augury in firefox is broken, this is my only way to effectively debug in angular on that browser. it is functional and I like it.

However, it does seem like sometimes the application's interface sort of breaks. At least it does for my custom components.

Kinda difficult to use because the "State" tab is located at the very end of the inspector panel, which means it definitely takes a lot more space than it needs,
not necessarily your fault, firefox is the one to blame here.
But I guess you could create a new major tab (along with "inspector", "debugger", "network", etc.) which contains the whole virtual dom tree, this way you can skip the native HTML elements which don't have angular state too! (although you can consider to add those as properties shown like `template` or `child` etc)

I don't understand how this extension works. I cannot find any hints about how to use it. Would be great if there'd be some screenshots or description.

not working in firefox