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, so you can keep track of your subscriptions and read/unread articles across devices.
I haven’t used the iOS version, but I highly recommend the macOS application!