Storybook

Storybook is a very nice tool for development of UI components.

The power of keeping components in Storybook is that you don't need to spin up the whole app to see how they render. Sometimes you also have to navigate to a lot of pages to find a UI component and also convulte the UI to a specific state to test the component. 

This is inefficient and slows down frontend development.

Instead, when you use a Storybook you can render a specific variation in isolation by passing in props, mocking data, or faking events.

Each component can have multiple stories. Each story allows you to demonstrate a specific variation of that component to verify appearance and behavior.