When working with a team of frontend developers/designers or working by yourself, having a components list of what css is available to you can be a real time saver. I don’t know how much longer I would have taken without bootstraps components. There is a small rails gem (component_library)[https://github.com/richarcher/component_library] that allows you to build your own component library. I am also using it to see my reactjs components. Feel free to check it out in action on (My Grocery Price Book)[http://www.my-grocery-price-book.co.za/components].