Looks cool! Reminds me of (YCs) Station with a focus on online communities. Hint: Says "0 beta users signed up since August 1st 2019" in the bottom left corner. Maybe refresh the cache?
Didn't know Station was from YC. Yack is a native app with a custom UI/UX built specifically for browsing online communities. As far as I remember, Station was another wrapper that points to actual websites, no?