Bluesky is testing Trending Topics, which will highlight popular and viral topics.

Threads is testing collections of profiles focused on popular topics and communities, such as basketball, style and fashion, food, books, pop culture, and more, curated by a few users in the US

Threads is rolling out an updated design for both iOS and Android. The update keeps the different feeds — For You, Following, and any custom feeds — visible on the home screen, making it easy for users to swipe between them.