Random ideas for special-purpose ActivityPub services that are not Mastodon, but you could subscribe to at will:
1. Sports league game updates
2. Stock market opening and closing prices, significant movement
3. Weather cameras in your region
4. Your own doorway security camera
5. Traffic disruptions in your region
6. Public transit schedule changes
7. New and updated tasks in your project management or source control tools
#SubscribableArchitecture #ActivityPub