QuickNav is a Unity Editor extension which allows you to jump back and forth in your navigation history. You can record history items as favorites and open them directly in the inspector.
In Unity every now and then you have to switch back and forth between assets in order to configure them interdependently. Be it because of texture assignment, material assignment, you name it. With 2 assets you can help yourself with 2 inspectors and locking one. However that's already very tedious, limiting and will get you only so far. Another thing is that you occasionally want to switch back and forth in history. Just like it's common in modern browsers. The Unity Editor doesn't have that feature yet. Besides Unity's own internal favorites mechanism is very limited as well.