The Paack design system provides ready-to-use components built with mdgriffith/elm-ui. It’s meant for primarily for internal use but is a very interesting project nonetheless and quite extensive, as you can see in the showcase.
Lamdera lets you build full-stack Elm apps with zero glue code. Dillon Kearns and Jeroen Engels discuss the philosophy and the 1.0 Lamdera release with Mario Rogic.