Cupola and the other apps.

How Cupola compares with the apps people ask about most, fact by fact, from each app's own website and store listing.

Cupola and nzb360nzb360 is Android only, with a paid Pro upgrade. Cupola is free and open source, on iPhone, iPad, Mac and Android.
Cupola and HelmarrHelmarr is Apple-only, with paid tiers and iOS 26 or later. Cupola is free and open source, on iPhone, Android and Mac from iOS 17.
Cupola and LunaSeaLunaSea published its final release and was archived. Cupola covers the same services and more, and it is free, open source and still developed.
Cupola and RuddarrRuddarr covers Radarr and Sonarr on iOS 26. Cupola covers seventeen services, runs on Android and iOS 17, and is free with no subscription.
Cupola and ArrMateyArrMatey ships as an Android APK, and its iOS app is built from source. Cupola installs on iPhone, iPad, Mac and Android today, free and open source.

Questions

Is there an nzb360 for iPhone?

nzb360 is Android only. Cupola covers much of the same ground on iPhone, iPad, Mac and Android, and it is free and open source. See Cupola and nzb360.

Is Cupola an alternative to LunaSea?

Yes. It covers what LunaSea did and more, and it is still being developed: LunaSea published its final release and was archived. Your connections need setting up again. See coming from LunaSea.