MacworldEvery year, we are introduced to a new version of iOS (alongside Apples other operating systems) at the Worldwide Developers Conference in June. It then marches through an extended beta-testing period before being released in September.But some of the key features of iOS are often planned to be introduced in subsequent updates. With iOS 18, the key Apple Intelligence feature didnt arrive until iOS 18.1, with additional AI features in iOS 18.2, with even more coming in iOS 18.4nearly half a year after the initial iOS 18 rollout.While Apple hasnt yet announced iOS 19, it has been hard at work on the big iPhone upgrade for quite a while and some rumors have started to leak out, and its starting to look like iOS 18 is somewhat of a preview of how iOS 19 will go. Based on the most reliable leaks and rumors, heres what you can expect when it arrives later this year.iOS 19: Release dateApple typically released the latest version of iOS to the public on the Monday following the iPhone launch event. Here are the release dates for the most recent versions of iOS:iOS 18: Monday, September 16, 2024iOS 17: Monday, September 18, 2023iOS 16: Monday, September 12, 2022iOS 15: Monday, September 20, 2021Based on recent history, we expect iOS 19 to release to the public on either Monday, September 15, or Monday, September 22.iOS 19: BetaEvery year, the new iOS is announced at WWDC with a beta test for developers released immediately (or at most, a day later). It often takes 4-6 weeks for the first public beta to be released, coinciding with the second or third build for developers. Apple releases the developer beta immediately after the WWDC keynote, which is expected to be on Monday, June 9.iOS 18: Monday, June 10, 2024iOS 17: Monday, June 5, 2023iOS 16: Monday, June 6, 2022iOS 15: Monday, June 7, 2021What follows is a string of beta releases, typically eight or so in total, before the software releases in September. We expect the same schedule this year with iOS 19. You can get ready for the beta by signing up for the iOS beta program now.iOS 19: CompatibilityWe expect iOS 19 to be compatible with every iPhone that supports iOS 18. That includes:iPhone 16iPhone 16 PlusiPhone 16 ProiPhone 16 Pro MaxiPhone 15iPhone 15 PlusiPhone 15 ProiPhone 15 Pro MaxiPhone 14iPhone 14 PlusiPhone 14 ProiPhone 14 Pro MaxiPhone 13iPhone 13 miniiPhone 13 ProiPhone 13 Pro MaxiPhone 12iPhone 12 miniiPhone 12 ProiPhone 12 Pro MaxiPhone 11iPhone 11 ProiPhone 11 Pro MaxiPhone XSiPhone XS MaxiPhone XRiPhone SE (2nd generation)Of course, it will also support the new iPhone 17 models that will launch around the same time, and the new iPhone SE 4 (which may be called the iPhone 16E).As always, some features wont be available on older models, as they lack the hardware resources for it. We do think the Apple Intelligence and Siri improvements will be available for all iPhone 16 and later models, though.iOS 19: New featuresMore Apple Intelligence with an LLM SiriThe most significant rumored change in iOS 19 so far is what some are calling an LLM (large language model) update to Siri.The idea is to make Siri truly conversational, much like the advanced voice mode on ChatGPT is today, but with the added advantage of having access to all the on-device data and history for your iPhone and Apple services.This would be combined with a further expansion of App Intents, which are hooks for developers to allow Siri to interact with and perform actions within their apps. These App Intents are getting a huge boost in iOS 18.4 to go along with Siris personal context update, and iOS 19 is said to expand the concept even further.One caveat: This next big evolution for Siri isnt expected to land until 2026, as part of an update to iOS 19. In other words, just as iOS 18.4 is the big Siri update for iOS 18, we can expect iOS 19.4 (or something like it) to be the big Siri update for iOS 19.Home app upgradesWhile not specifically mentioned in any of the current leaks or rumors, we find it hard to believe that Apple wont have some significant improvements to the Home app, HomeKit, and related services in iOS 19.Why? Well, Apple is expected to release a wave of new smart home products throughout 2025 and 2026. A new smart home hub is first: its an affordable 7-inch tablet that runs its own custom operating system (code-named Pebble) that has an interface similar to StandBy on iPhone. It will support Apple Intelligence, FaceTime, and tie in with other Apple services but isnt expected to have an App Store.After that, likely in 2026, Apple is said to be working on a new indoor smart security camera and a smart doorbell that would use Face ID to unlock your door the way it unlocks your phone. Further down the road, a smart home product with a movable screen on a robotic arm has been rumored, all of which will require deep integration with the iPhone and Home app.Its hard to imagine Apple pushing into first-party smart home products this much without updating the somewhat aging and clunky Home interface or introducing new features to it.