tvOS is iOS with different rules
tvOS shares Swift, SwiftUI, UIKit and AVFoundation with iOS, so teams with Apple experience move fast. But there is no touchscreen, no persistent local storage you can rely on, and strict limits on app size and on-device data, so content must come from the network and caches must tolerate eviction. Storage and state work differently. tvOS can evict cached data when space runs low, so anything important belongs in iCloud key-value storage, a keychain item or your own backend, with the app ready to rebuild its local state.
Siri Remote input and game controllers shape every interaction. Sharing a Swift package with your iOS app for networking, models and entitlement logic is sensible. Sharing interface code is usually not, because layouts and expectations differ. Game controllers, Siri voice search and the system's Apple TV app integration make tvOS more than a remote. Even non-game apps can accept controller input, and mapping those inputs deliberately avoids odd behaviors.
