coreui.io looks great. I'm working currently with https://github.com/almasaeed2010/AdminLTE/tree/v3-dev but v3 (Bootstrap 4) is in Alpha for a long time. Any of these B4 themes out there would be a good choose to see how to: * integrate with yarn / webpack in a rails 5 app * customize theme * add some custom page based vanilla js or jQuery * use Stimulus.js Not a ready-to-sale app, just a sample of usage of all of these (and perhaps more) topics