April 2020 Update :
We’ve updated our policy and pledge for watch face distributors in order to protect intellectual property rights, including, but not limited to, copyright, trademark, patent and design of brands/creators, and to offer the best curated experience for consumers.
If you are a new developer, you can use Galaxy Watch Designer or Tizen Studio to create watch faces for your own personal enjoyment. All new watch face sellers must submit an application and be approved to sell or distribute watch faces in Galaxy Store. Temporarily, the window to submit an application is closed. If you need an exception, contact firstname.lastname@example.org.
This only applies to Watch Face Apps not others.
Samsung Developer Program