Elm-UI is in a questionable state. Their github page originally said it was no longer maintained. Now they acknowledge that they are struggling to update to the latest version of Elm which caused many syntax breakages.
It looks like it is no longer maintained: https://github.com/gdotdesign/elm-ui/issues/100
cttet probably meant this: https://github.com/mdgriffith/elm-ui
As nhanb mentioned I meant https://github.com/mdgriffith/elm-ui. There is a great talk about it: https://www.youtube.com/watch?v=Ie-gqwSHQr0
However that was all for static UI though. Writing Elm app is still a pain if you are not a Javascript expert. Elm's implementation of the web API is minimal and the progress is extremely slow. In addition, most function that's in libraries in Javascript's ecosystem can not be directly used as you have to write Ports, which requires a lot of Javascript experience.