Apple still does not allow other software developers to implement and publish custom watch faces for Apple Watch (though you can purchase Apple Watch Hermès ($1,299 USD) with a new cool watch face).
Meanwhile, other wearable devices such as Samsung Galaxy Watch (that that runs on Tizen OS) already offer a wide selection of custom watch faces. We collected the top 12 custom watch face for Galaxy Watch here. Enjoy!
(click on images to view full-size photo)
Check this entertaining video as a summary of the article: