NetNewsWire
★★★★★
Clean, stable, fast, free, no-clutter and no-nonsense RSS/Atom newsfeed reader for macOS and iOS. You can read articles in the application or open them in the web browser of your choice.
It’s an app, not a service, so it’s not tracking you or inserting ads. That also means there’s no web version. But it can sync over iCloud, and with a variety of web-based newsreaders (including Feedly, Feedbin, InoReader, and FreshRSS), so you can keep track of your subscriptions and read/unread articles across devices. External actions can be set up with any Share extensions installed on the system, and you can choose an alternate web browser to open posts.
Unfortunately it doesn’t sync with Nextcloud News (yet).
I haven’t used the iOS version, but I highly recommend the macOS application!