Aeternum. The Apple Watch interface. It is still in development and lacks some features needed to use it as my main springboard interface. No folder support or spotlight search are the biggest omissions for me. This makes it hard to locate icons even though the app sorts the most used icons to the center, if desired. It scrolls around very nicely, bringing icons into view.
I have it set to an Activator action so I can switch it off and on using my pinky on Touch ID.