Chats, Reads (Long form-only client), Calendar, NIP-29 (Slack/Discord-like), Olas (Instagram-like), Reddit-like (user is de-emphasized on the layout), TikTok-like video feeds, YouTube-like Long form videos, nextdoor-like (location-specific), etc Basically each part of Amethyst could be a separate app with it's own notifications etc These all exist or have existed for some time, but they are not doing well.