Interface The iOS
user interface is based upon
direct manipulation, using
multi-touch gestures such as
swipe,
tap,
pinch, and
reverse pinch. Interface control elements include sliders, switches, and buttons. Internal
accelerometers are used by some applications to respond to shaking the device (one common result is the
undo command) or rotating it in
three dimensions (one common result is switching between portrait and landscape mode). Various
accessibility described in functions enable users with vision and hearing disabilities to properly use iOS. iOS devices boot to the lock screen. The lock screen shows the time and a user's lock screen widgets, which display timely information from apps. The lock screen also has two buttons, called Controls, which are only available on iPhone. These default to flashlight and camera, but they can be customized to any control available in Control Center and can also be removed. Upon unlock, a user is directed to the home screen, which is the primary navigation and information "hub" on iOS devices, analogous to the
desktop found on personal computers. iOS home screens are typically made up of app icons and
widgets; app icons launch the associated app, whereas widgets display live, auto-updating content, such as a
weather forecast, the user's email inbox, or a
news ticker directly on the home screen. Along the top of the screen is a status bar, showing information about the device and its connectivity. The Control Center can be "pulled" down from the top right of the notch or Dynamic Island on iPhones with
Face ID, or can be "pulled" up from the bottom to top of the screen on iPhones with
Touch ID, giving access to various toggles to manage the device more quickly without having to open the Settings. It is possible to manage brightness, volume, wireless connections, music player, etc. Scrolling from the top left to the bottom (or top to bottom on iPhones with Touch ID) will open the
Notification Center, which in the latest versions of iOS is very similar to the lock screen. It displays notifications in chronological order and groups them by application. From the notifications of some apps it is possible to interact directly, for example by replying to a message directly from it. Notifications are sent in two modes, critical alerts that are displayed on the lock screen and signaled by a distinctive sound and vibration (e.g.
emergency alerts or
severe weather alerts), accompanied by a warning banner and the app badge icon, and standard alerts which use a default sound and vibration. Both can be found in the Notification Center, and show for a set amount of time on the lock screen (unless the user has Notification Center allowed when locked). On iPhones with Touch ID,
screenshots can be created with the simultaneous press of the home and power buttons. In comparison to
Android, which requires the buttons to be held down, a short press does suffice on iOS. On iPhone with Face ID, screenshots are captured using the volume-up and power buttons instead. The camera application used a
skeuomorphic closing camera shutter animation prior to iOS 7. Since then, it uses a simple short blackout effect. Notable additions over time include
HDR photography and the option to save both normal and high dynamic range photographs simultaneously where the former prevents ghosting effects from moving objects (since
iPhone 5 on
iOS 6), automatic HDR adjustment (since
iOS 7.1), "live photo" with short video bundled to each photo if enabled (
iPhone 6s,
iOS 9), and a
digital zoom shortcut (
iPhone 7 Plus,
iOS 10). Some camera settings such as video resolution and frame rate are not adjustable through the camera interface itself, but are outsourced to the system settings. A new feature in
iOS 13 called "context menus" shows related actions when you touch and hold an item. When the context menu is displayed, the background is blurred. To choose from a few options, a selection control is used. Selectors can appear anchored at the bottom or in line with the content (called date selectors). Date selectors take on the appearance of any other selection control, but with a column for day, month, and optionally year. Alerts appear in the center of the screen, but there are also alerts that scroll up from the bottom of the screen (called "action panels"). Destructive actions (such as eliminating any element) are colored red. The official font of iOS is
San Francisco. It is designed for small text readability, and is used throughout the operating system, including third-party apps.
Home screen The home screen, rendered by
SpringBoard, displays
application icons and a dock at the bottom where users can pin their most frequently used apps. iOS home screens are typically made up of app icons and
widgets; app icons launch the associated app, whereas widgets display live, auto-updating content, such as a
weather forecast, the user's email inbox, or a
news ticker directly on the home screen. The home screen appears whenever the user unlocks the device, presses the physical "Home" button while in an app, or swipes up from the bottom of the screen using the home bar. The screen has a status bar across the top to display data, such as time, battery level, and signal strength. The rest of the screen is devoted to the current application. When a passcode is set and a user switches on the device, the passcode must be entered at the Lock Screen before access to the Home screen is granted. In iPhone OS 3,
Spotlight was introduced, allowing users to search media, apps, emails, contacts, messages, reminders, calendar events, and similar content. In iOS 7 and later, Spotlight is accessed by pulling down anywhere on the home screen (except for the top and bottom edges that open Notification Center and Control Center). In iOS 9, there are two ways to access Spotlight. As with iOS 7 and 8, pulling down on any homescreen will show Spotlight. However, it can also be accessed as it was in iOS versions 3 through 6. This endows Spotlight with Siri suggestions, which include app suggestions, contact suggestions and news. In iOS 10, Spotlight is at the top of the now-dedicated "Today" panel. With the release of
iPhone OS 3.2, users gained the ability to set a
wallpaper for the Home Screen. The feature was initially only available on the
iPad (1st generation) until the release of
iOS 4 a few months after the release of iPhone OS 3.2, which brought the feature to all iPhone and iPod Touch models that could run the operating system, with the exception of the
iPhone 3G and the
iPod touch (2nd generation) due to performance issues with icon animations.
iOS 7 introduced a parallax effect on the Home Screen, which shifts the device's wallpaper and icons in response to the movement of the device, creating a 3D effect and an illusion of floating icons. This effect is also visible in the tab view of Mail and Safari. Researchers found that users organize icons on their homescreens based on usage frequency and relatedness of the applications, as well as for reasons of usability and aesthetics.
System font iOS originally used
Helvetica as the system font. Apple switched to
Helvetica Neue exclusively for the
iPhone 4 and its
Retina Display, and retained Helvetica as the system font for older iPhone devices on iOS 4. With iOS 7, Apple announced that they would change the system font to Helvetica Neue Light, a decision that sparked criticism for inappropriate usage of a light, thin typeface for low-resolution mobile screens. Apple eventually chose Helvetica Neue instead. The release of iOS 7 also introduced the ability to scale text or apply other forms of text accessibility changes through Settings. With iOS 9, Apple changed the font to
San Francisco, an Apple-designed font aimed at maximum legibility and font consistency across its product lineup.
Folders iOS 4 introduced folders, which can be created by dragging an application on top of another, and from then on, more items can be added to the folder using the same procedure. A title for the folder is automatically selected by the category of applications inside, but the name can also be edited by the user. When apps inside folders receive notification badges, the individual numbers of notifications are added up and the total number is displayed as a notification badge on the folder itself. With increasing display sizes on newer iPhone hardware, iOS 7 updated the folders with pages similar to the home screen layout, allowing for a significant expansion of folder functionality. Each page of a folder can contain up to nine apps, and there can be 15 pages in total, allowing for a total of 135 apps in a single folder. In iOS 9, Apple updated folder sizes for iPad hardware, allowing for 16 apps per page, still at 15 pages maximum, increasing the total to 240 apps.
Notification Center Before iOS 5, notifications were delivered in a
modal window and could not be viewed after being dismissed. In iOS 5, Apple introduced
Notification Center, which allows users to view a history of notifications. The user can tap a notification to open its corresponding app, or clear it. Notifications are now delivered in banners that appear briefly at the top of the screen. If a user taps a received notification, the application that sent the notification will be opened. Users can also choose to view notifications in modal alert windows by adjusting the application's notification settings. Introduced with iOS 8, widgets are now accessible through the Notification Center, defined by 3rd parties. When an app sends a notification while closed, a red badge appears on its icon. This badge tells the user, at a glance, how many notifications that app has sent. Opening the app clears the badge.
Applications iOS devices come with
preinstalled apps developed by Apple including Mail, Maps, TV, Music, FaceTime, Wallet, Health, and many more. Applications ("
apps") are the most general form of application
software that can be installed on iOS. They are downloaded from the official catalog of the
App Store digital store, where apps are subjected to security checks before being made available to users. In June 2017, Apple updated its guidelines to specify that app developers will no longer have the ability to use custom prompts for encouraging users to leave reviews for their apps. IOS applications can also be installed directly from an IPA file provided by the software distributor, via unofficial ways. They are written using
iOS Software Development Kit (SDK) and, often, combined with
Xcode, using officially supported programming languages, including
Swift and
Objective-C. Other companies have also created tools that allow for the development of native iOS apps using their respective programming languages. Applications for iOS are mostly built using components of
UIKit, a programming framework. It allows applications to have a consistent look and feel with the OS, nevertheless offering customization. Elements automatically update along with iOS updates, automatically including new interface rules. UIKit elements are very adaptable, this allows developers to design a single app that looks the same on any iOS device. In addition to defining the iOS interface, UIKit defines the functionality of the application. At first, Apple did not intend to release an SDK to developers, because they did not want third-party apps to be developed for iOS, building
web apps instead. However, this technology never entered into common use, this led Apple to change its opinion, so in October 2007 the SDK for developers was announced, finally released on March 6, 2008. The SDK includes an inclusive set of development tools, including an audio mixer and an iPhone simulator. It is a free download for
Mac users. It is not available for
Microsoft Windows PCs. To test the application, get technical support, and distribute applications through
App Store, developers are required to subscribe to the Apple Developer Program. Over the years, the Apple Store apps surpassed multiple major milestones, including 50,000, 100,000, 250,000, 500,000, 1 million, and 2 million apps. The billionth application was installed on April 24, 2009.
App Library App Library automatically categorizes apps into folders based on their function or type and includes an alphabetical list of all installed apps. For example, it might group all social media apps into one folder and productivity apps into another. Users can quickly find and access apps by using the search bar at the top of the App Library. Users can choose to hide specific app pages from the home screen, making it easier to focus on the apps they use most frequently.
Storage iOS enforces strict sandboxing to maintain security and privacy. Apps are generally limited to accessing their own containers and specific system-provided directories, such as the Photos library. To access files outside of their sandbox, iOS uses mechanisms like document pickers, file providers, and app extensions. iOS 8 introduced the Document Picker and Document Provider extensions as part of the document interaction controller. This allows apps to open, save, and interact with documents stored in a central location or cloud storage services. With iOS 11, Apple introduced the
Files app and the File Provider extension, providing a central location for users to manage and organize their files. Apps can integrate with the Files app to make their documents accessible and editable directly from the Files app. The storage of iOS devices can be expanded through
iCloud, the Apple's cloud-based storage solution that provides 5GB of storage for free to all users, while other plans require a paid subscription. iCloud Drive allows users to store various types of files, such as documents, presentations, and spreadsheets, in the cloud. These files can be accessed across multiple devices as long as the user is signed in with the same Apple ID.
Accessibility iOS offers various accessibility features to help users with vision and hearing disabilities. One major feature,
VoiceOver, provides a voice reading information on the screen, including contextual buttons, icons, links and other
user interface elements, and allows the user to navigate the operating system through gestures. Any apps with default controls and developed with a UIKit
framework gets VoiceOver functionality built in. One example includes holding up the iPhone to take a photo, with VoiceOver describing the photo scenery. As part of a "Made for iPhone" program, introduced with the release of
iOS 7 in 2013, Apple has developed technology to use
Bluetooth and a special technology protocol to let compatible third-party equipment connect with iPhones and iPads for streaming audio directly to a user's ears. Additional customization available for Made for iPhone products include battery tracking and adjustable sound settings for different environments. Apple made further efforts for accessibility for the release of
iOS 10 in 2016, adding a new pronunciation editor to VoiceOver, adding a
Magnifier setting to enlarge objects through the device's camera, software
TTY support for deaf people to make phone calls from the iPhone, and giving tutorials and guidelines for third-party developers to incorporate proper accessibility functions into their apps. In 2012, Liat Kornowski from
The Atlantic wrote that "the iPhone has turned out to be one of the most revolutionary developments since the invention of
Braille", and in 2016, Steven Aquino of
TechCrunch described Apple as "leading the way in assistive technology", with Sarah Herrlinger, Senior Manager for Global Accessibility Policy and Initiatives at Apple, stating that "We see accessibility as a basic human right. Building into the core of our products supports a vision of an inclusive world where opportunity and
access to information are barrier-free, empowering individuals with disabilities to achieve their goals". Criticism has been aimed at iOS depending on both internet connection (either WiFi or through iTunes) and a working
SIM card upon first activation. This restriction has been loosened in iOS 12, which no longer requires the latter.
Multitasking Multitasking for iOS was first released in June 2010 along with the release of
iOS 4. Only certain devices—
iPhone 4,
iPhone 3GS, and
iPod Touch 3rd generation—were able to multitask. The
iPad did not get multitasking until iOS 4.2.1 in that November. The implementation of multitasking in iOS has been criticized for its approach, which limits the work that applications in the background can perform to a limited function set and requires application developers to add explicit support for it. Before iOS 4, multitasking was limited to a selection of the applications Apple included on the device. Users could however "
jailbreak" their device in order to unofficially multitask. Starting with iOS 4, on third-generation and newer iOS devices, multitasking is supported through seven background
APIs: • Background audio – application continues to run in the background as long as it is playing audio or video content • Voice over IP – application is suspended when a phone call is not in progress With the introduction of iOS 9, the application switcher received a significant visual change; while still retaining the card metaphor introduced in iOS 7, the application icon is smaller, and appears above the screenshot (which is now larger, due to the removal of "Recent and Favorite Contacts"), and each application "card" overlaps the other, forming a
rolodex effect as the user scrolls. Now, instead of the home screen appearing at the leftmost of the application switcher, it appears rightmost. In
iOS 11, the application switcher receives a major redesign. In the iPad, the
Control Center and app switcher are combined. The app switcher in the iPad can also be accessed by swiping up from the bottom. In the iPhone, the app switcher cannot be accessed if there are no apps in the
RAM.
Ending tasks In iOS 4.0 to iOS 6.x, briefly holding the icons in the application switcher makes them "jiggle" (similarly to the homescreen) and allows the user to
force quit the applications by tapping the red minus circle that appears at the corner of the app's icon. Clearing applications from multitasking stayed the same from iOS 4.0 through 6.1.6, the last version of iOS 6. As of iOS 7, the process has become faster and easier. In iOS 7, instead of holding the icons to close them, they are closed by simply swiping them upwards off the screen. Up to three apps can be cleared at a time compared to one in versions up to iOS 6.1.6.
Task completion Task completion allows apps to continue a certain task after the app has been suspended. As of iOS 4.0, apps can request up to ten minutes to complete a task in the background. This doesn't extend to background uploads and downloads though (e.g. if a user starts a download in one application, it won't finish if they switch away from the application).
Siri Siri () is a
virtual assistant integrated into iOS. The assistant uses voice queries and a
natural-language user interface to answer questions, make recommendations, and perform actions by delegating requests to a set of Internet services. The software adapts to users' individual language usages, searches, and preferences, with continuing use. Returned results are individualized. Originally released as an app for iOS in February 2010, it was acquired by Apple two months later, and then integrated into
iPhone 4S at its release in October 2011. At that time, the separate app was also removed from the iOS
App Store. Siri supports a wide range of user commands, including performing phone actions, checking basic information, scheduling events and reminders, handling device settings, searching the Internet, navigating areas, finding information on entertainment, and is able to engage with iOS-integrated apps. With the release of
iOS 10 in 2016, Apple opened up limited third-party access to Siri, including third-party messaging apps, as well as payments, ride-sharing, and Internet calling apps. With the release of
iOS 11, Apple updated Siri's voices for more clear, human voices, it now supports follow-up questions and language translation, and additional third-party actions.
iOS 17 enabled users to activate Siri by simply saying "Siri", while the previous command, "Hey Siri", is still supported.
Game Center Game Center is an
online multiplayer "social gaming network" released by Apple. It allows users to "invite friends to play a game, start a multiplayer game through matchmaking, track their
achievements, and compare their high scores on a
leaderboard." iOS 5 and above adds support for profile photos. Game Center made its public debut on the iPad with iOS 4.2.1. There is no support for the
iPhone 3G,
original iPhone and the
first-generation iPod Touch (the latter two devices did not have Game Center because they did not get iOS 4). However, Game Center is unofficially available on the iPhone 3G via a hack. == Supported processors ==