It's great to see more people coming to Elm and share their explorations. Andreas Kroepelin has a very detailed writeup about his experience creating a simple card game. Link
Ryan Frazier is writing a series of posts about implementing a calculator in Elm. Going from the initial idea, to project setup, all the way to testing. The code is open source and there are already 3/11 parts written. Link
Luca is explaining how to create masonry layout in Elm. If you're planning on building a gallery of images similar to Pinterest, then it's a great writeup. The demo has lots of configuration options too so worth playing with. Link
An advanced topic on partial defunctionalization. It is generally considered a bad practice to store functions in your model, however it is sometimes tricky to avoid it when creating a package. What can you do about it? Link
A collection of Elm UI widgets. Think of it as a fancy CSS framework like Tailwind or Bulma that you can quickly connect and use its buttons, dropdowns, and other components. Check out the demo. Link
While not really a package, and the Christmas is long gone, but an interesting project nevertheless: Elm Christmas. Link
Dillon Kearns doesn't stop amazing me. He's having regular live coding sessions of various complexity and covering different topics. All of these meetings are then publish on his YouTube channel. You can browse the upcoming events on the Incremental Elm page.