Based off of Valentino Gagliardi's tutorial, React Redux Tutorial for Beginners.
This is a pure Redux example integrated into a small React app. No react-redux add-on here. I'm not necessarily following best practices, because I wanted to simplify the file structure as much as possible to make it more clear.
All Redux-specific files are in src/store/. The App.js component only imports the store, because it only listens (subscribes) for changes. The Child.js component imports the store and action function, because it sends updates (dispatches) to the store.