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Apple released iOS 27 to the public on 14 September 2026, following its preview at WWDC in June. As with every major release, most iPhone owners will be on it within months, which means your app needs to behave properly on it whether or not you planned an update. Here is what changed, and which parts are worth your developer's time this autumn.
The headline changes
Apple framed iOS 27 around three things: a rebuilt Siri with its own dedicated app, new child safety and parental controls, and a long list of system improvements. Alongside those came more AI features across Photos, Safari, Calendar and Reminders, a new system-wide dictation experience in the keyboard, and refinements to the Liquid Glass design introduced in iOS 26, including a transparency control for users.
Device support is generous. iOS 27 runs on every iPhone that supported iOS 26, back to the iPhone 11 and second-generation iPhone SE. Apple Intelligence features still need an iPhone 15 Pro or newer.
Worth knowing: a couple of features shown at WWDC were pulled before release. If you planned app features around something from the June keynote, check that it actually shipped in 27.0 before you build on it.
What it means for your app
Siri and App Intents
Siri is the biggest story of this release, and the way your app plugs into it is through Apple's App Intents framework. If your app already exposes actions to Shortcuts and Siri ("book my usual table", "show today's jobs", "check my order"), those become more useful as Siri gets better at understanding requests. If it exposes nothing, your app is invisible to the assistant your customers are being encouraged to use.
You do not need to expose everything. Two or three genuinely common actions are worth more than twenty that nobody asks for.
Liquid Glass, one year on
iOS 26 introduced Liquid Glass, Apple's translucent design material for navigation bars, tab bars, sheets and controls. Many apps picked up the new look automatically when rebuilt with the latest Xcode. iOS 27 refines it and gives users more control over transparency, which is good news for readability but is also a reason to re-test screens where text sits on top of busy images or maps.
If your app still looks like it was designed for iOS 18, it will increasingly stand out next to everything else on the phone. That is not an emergency, but it should be on next year's plan.
Apple Intelligence and on-device models
Since iOS 26, Apple's Foundation Models framework has let developers use the same on-device model that powers Apple Intelligence, without per-request costs and without sending data to a server. Features like summarising a long job sheet or suggesting a reply can run entirely on the phone. The limits are real: it only works on Apple Intelligence-capable devices with the feature enabled, and only in supported languages, so it should enhance a feature rather than be the only way to use it.
A practical iOS 27 checklist
- Test the current App Store build on iOS 27 before anything else. Most problems after a major release are small layout or permission issues, but they show up in reviews quickly.
- Rebuild with the current Xcode and check every screen that uses system navigation, sheets or tab bars.
- Check text legibility with different transparency settings, particularly over photos and maps.
- Review permission prompts. Each release tightens privacy a little. Make sure every prompt explains clearly why you need access.
- Pick two or three actions to expose to Siri through App Intents if you have not already.
- Decide on your minimum iOS version. Supporting very old versions slows development. Many business apps support the current and previous major release.
What can wait
New consumer features in Apple's own apps rarely require anything from you. Genmoji, Image Playground changes and CarPlay video apps are interesting, but unless your product lives in those areas, they belong in a "maybe next year" list rather than this month's sprint.
Point releases matter more than people think. iOS 27.0.1 arrived within a fortnight to fix a Face ID issue, and 27.2 was already in beta by October. Plan a quick check after each point release rather than one big test in September.
Keeping on top of yearly releases
Every September brings a new iOS and every year Apple raises the bar for submissions. Apps that are left alone for two or three years tend to need a much bigger, more expensive catch-up than apps that get a modest update each year. Treat the annual release as routine maintenance, not a surprise.
At Clickshow, we look after iPhone and Android apps for UK businesses, including the yearly round of OS testing and updates. If you are not sure how your app is holding up on iOS 27, our maintenance and support plans are designed for exactly this kind of work.
