Most of the home screen replacements out there are just variations on a theme. There are scrollable panels, icons, and an app drawer. Foneclay is something entirely different. With this app, you can turn your phone into functional, though bizarre art.
The app itself is essentially just a front end for downloading and installing the artistic home screen apps. Tap on one that looks interesting, and you can preview the UI before you download. Each home screen is installed like any other non-Play Store app from system dialogs. Some of the options are more impressive than others, with animations and really cool art. Is any of it as functional as a real home screen? Probably not. Still, if you want your home screen of consist of a giant icon-wielding octopus, this is the only game in town.
Foneclay is currently stocked with around 30 "fones," all of which are free. Presumably paid fones will happen later. I don't think I could use these as my full-time home screen, but I'm sure someone will. It's free, so you should at least check this out for the novelty factor.