iOS Programming

I’m currently building an Android app that utilizes Android Keystore and Shared Preferences to securely manage user accounts. I’m planning to build an iOS version of the app and I’m curious if there are equivalent technologies for iOS. Specifically, I’m wondering if there’s an equivalent to Android Keystore on iOS, or if the iCloud sync API would be a suitable alternative. I’ve seen other iOS apps use iCloud for syncing content, such as YouTube rss channels (Unwatched), but I’m not sure if that’s the same as Keystore. Is there a similar secure storage option on iOS, or would iCloud Key-Value Storage or CloudKit be the best options?