iPhone (Apple smartphone series)

Operating system

The operating system is iOS (formerly called iPhone OS), which provides the home screen and the installed applications (apps) for interaction with the user. The home screen is the actual user interface of iOS, from which applications that are already preinstalled or downloaded from the App Store can be accessed. In general, iOS has a strong connection to Apple services, such as the iTunes Store, App Store or iCloud.

The core of iOS is an adapted macOS, which is the operating system of the Mac. However, the range of functions is smaller due to restrictions, such as the lack of root access.

Operating concept

The iPhone is operated almost entirely via the multi-touch screen, with the graphical user interface used displaying only one program window at a time. The screen is usually divided as follows:

• An approximately 4 mm high status bar at the top of the screen (display of signal strength, provider, mobile mode [LTE, 3G, EDGE, GPRS], battery status, etc.).
• Below this is a menu area about one centimeter wide with the program name and, if necessary, a few menu items (such as a + to add new entries, an edit to edit entries, or day, month and year to switch calendar views).
• Below this is the actual program window
• If necessary, there is another menu bar below the program window, with which programs can be switched into different modes (for example, the clock between world time, timer, alarm clock and stopwatch).

Since iOS 7, many elements of the operating system, such as the status list and menu area, are slightly transparent and blurred, showing the program content that is behind them.

The touch screen is operated with various finger movements:

• Tap: The underlying function is executed.
• Double-tap: Zooms in or out on a section of the image.
• Tap and hold: A magnifying glass function will appear. By moving the pressed finger, the text marker can be moved to a desired position. If necessary, an options menu is displayed.
• Swipe (place your finger in motion, swipe across the screen, release): Used to scroll through lists (addresses and the like; vertical swipe motion) or views (weather images, Cover Flow, web pages; horizontal swipe).
• Tap and drag: Moves the view on the screen (for example, for maps or HTML pages).
• Grab and move: For certain functions, tapping an object (e.g., caller list, weather location list) at a specific location indicated by three horizontal bars allows you to move the object to another location in the list by moving your finger.
• Spreading and squeezing: This gesture is performed with two fingers moving away from or towards each other. The view on the screen is enlarged or reduced (for example, in the web browser, when viewing photos and maps).

With the introduction of 3D Touch on the iPhone 6s, more content, options, and previews can be displayed by pressing on the screen (peek and pop).

Text is entered using an on-screen keyboard displayed in the program window. Umlauts and other additions of Latin characters can be entered by holding instead of typing the basic key and then moving the finger to the displayed character. If the keyboard layout is set to German, German umlauts and the 'ß' are directly available as keys. The entered text is displayed in a small field at the top of the screen or directly above the keyboard. The accuracy of the input depends on the size of the fingers and the manual skill of the operator, whereby an adaptive correction function supports the input.

Apple tries to give disabled people access to the iPhone as well. For this reason, the iPhone has had numerous operating aids for people with hearing, visual and physical disabilities since the iPhone 3GS. The iPhone enables especially visually impaired users an accessible operation through the gesture-based screen reader VoiceOver. In addition, the iPhone has numerous optical adjustment options such as an integrated zoom function, which allows people with a visual impairment to use the iPhone.

Answering machine

With Visual Voicemail, recorded messages can be clearly displayed in a list. This eliminates the need to call the answering machine. The mobile network providers must operate servers with Apple software for this service. In Germany, Austria and Switzerland, the network operators Vodafone, Telekom, O2, Swisscom, Sunrise Communications and Salt Mobile offer this service in their iPhone tariffs.

Synchronization

Contacts (names, phone numbers, addresses, email addresses), calendar appointments and events, email account settings, web page bookmarks, notes, ringtones, music, audiobooks, photos, podcasts, movies, TV shows, music videos, and applications downloaded from the iTunes Store can be synced with a computer via iTunes. iPhone can also be synced via a Microsoft Exchange server or, as is now common, the company's own iCloud service.

Other programs

In his iPhone launch keynote, Steve Jobs pointed to Cocoa Touch as the main application programming interface (API) for iPhone software.

At WWDC 2007, it was first announced that other manufacturers could not write classic applications for the iPhone and that this would instead be solved via web application based on open standards such as Ajax that could be displayed in the Safari web browser. From Safari, iPhone's own applications such as Google Maps or the phone function could then be used. A version of Safari for Microsoft Windows, which was also announced, enabled Mac OS X-independent testing of such applications for developers from the Windows world. Through the sandbox principle, also known from Java, the iPhone should be better protected against malfunctions and manipulation by software.

On October 17, 2007, after numerous protests from developers, Steve Jobs announced a development tool, including native apps, on Apple's website as Hot News. The development system (Software Development Kit (SDK)) had a long development time, because Apple tried to realize two opposite goals - to provide an open platform for developers and at the same time to protect the iPhone from viruses, malware, attacks on private data, etc.. Then, on March 6, 2008, iPhone OS version 2.0 was unveiled at an event, supporting the iPhone SDK along with Microsoft Exchange Server and other network protocols. The software has been publicly available since July 11, 2008.

Apple developed a mobile variant of its Cocoa framework called Cocoa touch for the iPhone. The SDK is delivered together with a new version of Apple's integrated development environment Xcode. It also includes an iPhone simulator, which makes it largely possible to test the applications on the Mac during the development phase. The applications will be distributed through the App Store. Developers can set the price for their software themselves, but Apple takes 30 percent of that as a commission. While the SDK itself can be obtained for free from Apple's developer sites, publishing to the App Store requires a paid developer account priced at $99 (standard) or $299 (enterprise apps) per year.

In the meantime, programmers had established methods to make programs run on the device that are not executed as web applications (so-called native applications). In July 2007, hackers succeeded for the first time in running a Hello World program on the iPhone with the help of a jailbreak. Apple was initially neutral to these programming approaches; thus, it did not interfere with the developments, but also made no effort to maintain the runnability of such programs with later versions of the operating system. The development of the jailbreak took further progress and became an arms race between jailbreak developers and Apple in the heyday of the jailbreak, the years 2010 to 2012. In the meantime, however, the jailbreak has seen a significant decline.

Other operating systems

Since the iPhone has been on the market, there have been efforts to replace the proprietary operating system iOS with an open source one. In particular, the programmers planetbeing and CPICH have promoted this development. Their development work has resulted in iDroid. Part of it is the open source boot loader OpeniBoot, which can be installed on the first two iPhone generations as an alternative to Apple's iBoot. OpeniBoot allows you to boot any firmware on the iPhone. (Apple's iBoot only boots firmware signed by Apple).

In December 2008, PlanetBeing demonstrated a Linux distribution on the iPhone for the first time, followed by Google's Android operating system in April 2010. The user has the choice of which system to boot through a boot menu - iOS remains bootable.

In practice, alternative operating systems have not yet become established, as the only public Android ports only work with devices that use older processors. On newer iPhones that use other processors, the installation of alternative operating systems is meanwhile hardly possible due to increasingly closed security gaps.