Arca.so

Arca.so is described as a portal for browsing and curating the internet, which aligns with content discovery and recommendation. The app allows users to 'curate' content, implying user profiles and the ability to follow others' minds, which suggests user profiles and following. The description also mentions 'discover unheard voices', indicating a search and discovery function. However, the core features of a publishing platform like a rich text editor, monetization, and detailed engagement metrics for writers are not evident from the provided content, making it less of a direct match for a publishing platform like Medium.