EMZETT.iOS
In short: Apple’s mobile operating system for iPhones — known for a more closed ecosystem than Android (apps only via the App Store, stricter review processes).
In more detail: Apps are primarily developed in Swift and distributed via the App Store, with a stricter review process than Google’s Play Store. The more closed system (no official sideloading outside EU regulations, stricter sandbox rules) is generally considered more secure, but also restricts developer freedom more than Android.
In Depth
The closed control model
Apple’s strict control model shows up at several levels: every app goes through a manual review by Apple before release (rule violations like hidden features, unclear data use, or bypassing the in-app purchase commission lead to rejection), apps run in a stricter sandbox with less system access than on Android (e.g. more restricted access to other apps or the file system), and traditionally sideloading (installing apps outside the App Store) was technically completely blocked. The EU has now, with the Digital Markets Act (DMA), forced alternative app stores and sideloading for iOS devices within the EU — Apple had to open technical interfaces for this that it had previously deliberately kept closed, but continues to resist with additional fees/security requirements for third-party stores.
Development and app distribution
Apps are primarily developed in Swift (Apple’s own, modern language) or the older Objective-C, with Apple’s development environment Xcode — which only runs on macOS, effectively tying iOS development to Apple hardware. The App Store review process typically takes one to several days and can reject apps without a detailed explanation, which regularly frustrates developers, but at the same time leads to overall fewer malware/scam apps in the App Store than in more open ecosystems.
Lower fragmentation
Because Apple controls both hardware and operating system (vertical integration), device fragmentation on iOS is considerably lower than on Android: Apple rolls out new iOS versions to almost all supported devices at once (often even iPhones 5-6 years old), which considerably eases testing for developers — fewer device combinations, a more up-to-date user base (most iPhone users are on the latest iOS version within a few months of release) compared to the fragmented Android update landscape, where manufacturers and carriers often delay updates for months or years, or drop support entirely.
Economic model
iOS users on average spend considerably more money on apps and in-app purchases than Android users, which is why many development teams prioritise iOS despite its smaller global market share (compared to Android), or even develop exclusively for it — an effect partly tied to the generally higher-priced iPhone customer segment.
App distribution with no classic APK equivalent
Unlike Android, there’s no direct, common equivalent to the APK file for end users on iOS — apps are distributed practically exclusively via the App Store (or, since the DMA, increasingly via alternative stores in the EU), the app package format (.ipa) is primarily relevant for developers and internal test distribution, not for the everyday user, who simply “installs” an app without ever seeing an installation file.