Changes since 5.1.3:
Universal (Intel + ARM)
Big Sur app icon
Big Sur UI (when running on Big Sur)
App is now sandboxed
Syncing via iCloud
Syncing via BazQux, Inoreader, NewsBlur, The Old Reader, and FreshRSS
Special support for Twitter and Reddit feeds
Share extension, so you can send URLs to NetNewsWire
Preference to change article text size
Preference to set preferred browser
External link, when available, shows in article view
High resolution icons in the sidebar (when available)
Notifications let you mark starred/read from the notification
Refreshed UI for adding sync accounts