• iOS (previously iPhone OS) is a mobile operating system developed and distributed by Apple Inc.

• Originally unveiled in 2007 for the iPhone, it has been extended to support other Apple devices such as the iPod Touch (September 2007), iPad (January 2010), iPad Mini (November 2012) and second-generation Apple TV (September 2010).

• Unlike Microsoft's Windows Phone and Google's Android, Apple does not license iOS for installation on non-Apple hardware.

• As of August 2013, Apple's App Store contained more than 900,000 iOS applications, 375,000 of which were optimised for iPad.

• Apps have collectively been downloaded more than 50 billion times.

• There were 410 million devices activated. According to the special media event held by Apple on September 12, 2012, 400 million devices had been sold by June 2012.

• The user interface of iOS is based on the concept of direct manipulation, using multi-touch gestures.

• Interface control elements consist of sliders, switches, and buttons.

• Interaction with the OS includes gestures such as swipe, tap, pinch, and reverse pinch, all of which have specific definitions within the context of the iOS operating system and its multi-touch interface.

• 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 from portrait to landscape mode.

• iOS is Apple's mobile version of the OS X operating system used on Apple computers.

• Major versions of iOS are released annually. The current release, iOS 7, was released on September 18, 2013.

• In iOS, there are four abstraction layers: the Core OS layer, the Core Services layer, the Media layer, and the Cocoa Touch layer.

• The current version of the operating system (iOS 7.0), (iOS 7.0.1 for iPhone 5C and iPhone 5S), dedicates 1–1.5 GB of the device's flash memory for the system partition, using roughly 800 MB of that partition (varying by model) for iOS itself.

• iOS currently runs on the iPhone, iPad, iPad Mini, iPod Touch and Apple TV.

iOS Technology LayersCore OS LayerThe Core OS Layer occupies the bottom position of the iOS stack and, as such, sits directly on top of the device hardware. The layer provides a variety of services including low level networking, access to external accessories and the usual fundamental operating system services such as memory management

Core Services Layer Core Services layers contain the fundamental interfaces for iOS, including those used for accessing files, low-level data types, Bonjour services, network sockets, and so on. These interfaces are mostly C-based .

Media LayerMedia Layer allows you to create the best multimedia experience available on a mobile device with the frameworks in the Media layer. More advanced technologies that use interfaces based on a mixture of C and Objective-C is used in Media Layer.

Cocoa Touch LayerFor iOS, there is a similar API(Application Programming Interface) called Cocoa Touch which includes gesture recognition, animation, and a different user interface library, and is for applications for the iOS operating system, used on Apple devices such as the iPhone, the iPod Touch, and the iPad.Cocoa Touch is primarily written in Objective-C

iOS: A visual history

iOS 1: The iPhone is borniOS 1.0 Devices Features

Released06 / 2007

iPhone 2G Core iOS UI

Multitouch gestures

Mobile Safari

iPod

Visual Voicemail

Maps

iTunes SynciOS 1.0 also introduced a new computing paradigm that broke from smartphone tradition: hiding the file system from the user

iOS 2: AppsiOS 2.0 Devices Features

Released07 / 2008

iPhone 3G,iPhone 2G,iPod Touch 1st Gen

Native 3rd-party apps

App Store

Microsoft Exchange support

MobileMe

Contact Search

The App Store used Apple's already established base of iTunes music customers

iOS 3: Features

iOS 3 was all about filling in most of the major complaints and "gotchas"

iOS 3.0 Devices Features Released06 / 2009

iPhone 3GS,iPhone 3G,iPhone 2G*,iPod Touch 2nd Gen,iPod Touch 1st Gen*

Cut, copy, paste

Voice Control

MMS

Spotlight search

Push notifications

USB & Bluetooth tethering

Landscape keyboard

Find my iPhone

iOS 3.2: The iPad arrives

iOS meets the big screen

iOS 3.2 Devices Features Released04 / 2010

iPad Support for iPad resolution

New app views for iPad

Location based on Apple data

Bluetooth keyboard support

iBooks

iOS 4: Multitasking

The major question at the time was whether Apple's unique implementation of multitasking was a distinction without a difference

iOS 4.0 Devices Features Released06 / 2010

iPhone 4,iPhone 3GS,iPhone 3G*,iPod Touch 3rd Gen,iPod Touch 2nd Gen*

Multitasking

Home screen folders

Face Time video chat

Unified email inbox

Threaded email messages

Retina Display support

iAd support

iOS 5: Siri and much more

As a natural user interface, it's one of the more promising things we've seen come along in some time

iOS 5.0 Devices Features

Released10 / 2011

iPhone 4S.iPhone 4,iPhone 3GS,iPad,iPad 2iPod Touch 4th Gen,iPod Touch 3rd Gen

Siri

Notification Center

PC-free

iTunes Wi-Fi Sync

iMessage

iCloud

iOS 6: Goodbye, Google Maps

Realizing Apple's dream of a Google-free iPhone

iOS 6.0 Devices Features ReleasedFall 2012

iPhone 5iPhone 4S,iPhone 4,iPhone 3GS,iPad miniiPad 4th GeniPad 3rd GeniPad 2iPod Touch 4th GeniPod Touch 5th Gen

Homegrown Maps and turn-by-turn navigation

Siri enhancements

Facebook integration

Passbook

iCloud Tabs

Mail enhancementsFaceTime over cellular

iOS 7: Hello, Jony IveiOS 7.0 Devices Features ReleasedFall 2013

iPhone 5s,iPhone 5c,iPhone 5,iPhone 4S,iPhone 4,iPad mini,iPad 4th Gen,iPad 3rd Gen,iPad 2,iPod Touch 5th Gen

Visual overhaul

Control Center

Airdrop

Refreshed core apps

iTunes Radios

FaceTime Audio

Clash of the titans: iOS 7 vs Windows Phone 8 vs Android 4.3 comparison

iOS 7, Windows Phone 8 and Android 4.3 are the top three mobile operating systems in the world

IOS• Apple’s iOS is now in its seventh version, and is called the iOS 7.• Drastically redesigned iOS was released on 18th September 2013• It’s already Apple’s most popular OS ever

Windows Phone• Windows Phone 8 is the second generation of the Windows Phone mobile

operating system from Microsoft.• Released in October 2012• Microsoft’s mobile OS has showed a 133% growth over the year.

Android• Android is a Linux-based operating system, which operates on

smartphones made by a variety of mobile-makers. • The latest version is the Jelly Bean 4.3 • Released in July 2013.

User Interface

• The iOS 7 has completely overhauled its previous user interface. In fact, it is being billed as the biggest change to iOS since the introduction of the iPhone. New icons, layering, gyroscope-driven parallaxing, and translucency are some of its new features.

• iOS 7 has made multitasking a real pleasure! Double tapping the home button will open up a row of active apps, and all you need to do to close one is to swipe it up. Tap an app, and it will open up in full screen.

• And then there’s the Control Centre, which gives you quick access to commonly used apps, controls, and settings. You can simply swipe across the screen to adjust the brightness, turn on the Wi-Fi, and more.

• The iOS 7 UI looks extremely appealing, and works extraordinarily well.

iOS 7

Windows Phone 8 • The user interface on a Windows phone consists of the Start screen, which is

filled up with Live Tiles that are dynamic in nature and updated in real time. • These squares are linked to different apps, functions, contacts, etc. You have the

freedom to add or delete tiles, and to rearrange them as per your liking.• Many features on this UI are clubbed into hubs, which essentially integrates local

and online content. • For example, the Pictures hub contains photographs from the user’s social

networking accounts, as well as those on the device. You can even comment on images within the hub, and they will then get updated

• The Windows Phone 8 is great for multitasking. Apps run in the background, and by pressing a button you can switch between different active apps.

• Microsoft’s mobile operating system does not come with a Control Centre. You’ll need to go to the Settings menu to make changes. Since there is no centralized notification centre, you can access controls through the Live Tiles as well.

Android 4.3 • Android 4.3 is perhaps the best OS for multitasking.• Press the multitasking button, and you will get an entire list of active applications.

Apps run in the background, and can even produce expanded notifications with images, graphs, and more.

• Notification on Android 4.3 are live and dynamic, but the list can be cleared with a simple swipe.

• You may be able to access quick settings and functions by adding the Power Control widget on to your home screen.

Security

• Apple has released the iOS 7.0.2 update, which now fixes the bug that previously allowed anyone to bypass the Lock screen passcode.

• To help you remember your account usernames and passwords for different sites, this OS allows you to store all your information on the I Cloud.

• When you login to a website, the details will automatically get filled up.• Apple promises that all passwords will be encrypted. • iOS 7 keeps track of app permissions at the root level. • This means that you can adjust your privacy settings for each app individually. • You also have the choice to activate the Limit Ad Tracking feature, which will block

marketers from planting cookies on your phone. • There’s also an icon that points out when an app has accessed your location data. • Furthermore, Apple has introduced a password-protect reset feature, which

ensures that stolen Apple devices can’t be used without the owner’s Apple ID and password.

Windows Phone 8 • Windows Phone 8 encryption gets activated the minute your device is turned on. • This system, based on Bit locker, encrypts your entire device. Microsoft has also

added a new feature called the Safe Boot Feature. • Simply put, it makes it difficult for any component with an incorrect digital

signature to be loaded on to your Windows phone.• Every Windows phone will get a unique key burned into a chip, and only those

functions will work that match this digital signature. • In addition to all this, the OS runs all apps as third party Marketplace apps.

Microsoft has however not added any feature that protects devices if they get stolen.

Android 4.3 • Android 4.3 gives you the freedom to restrict certain users from accessing content

on your device. • can also stop individual apps from getting your contact information or location

data. • This OS, like iOS 7, does have features that protect phones in case they get stolen

but you have to add them using Play Store!

Customizability

• iOS 7 does not allow for a lot of customization. • Like Android’s live wallpapers, Apple gives you the choice to use dynamic

wallpapers on your home and lock screens.• However, there is not a whole lot of choice yet.

• Windows Phone 8, like iOS 7, does not give its users a lot of liberty to customize.• Live Tiles can be resized, and the lock screen can be used to add widgets, photos,

and notifications.• You can select a theme colour, and your UI elements, including third-party apps,

will all coordinate accordingly

Android 4.3 • Android Jelly Bean is the king of customization! • You can be flexible with wallpapers, widgets, apps, custom launchers, and lots

more.• You can download content from the Google Play Store, and essentially customize

your device anyway you like.

Music iOS 7

• Apple has launched iTunes Radio, which is a free streaming music service.• This feature is currently available to only those users living in the US, but it’ll soon be rolled out in other

countries.• You can listen to channels based on genres, and can create your own channel containing your favourite

music.• iTunes Radio will save users preferences, thereby playing music based on listening history.

Windows Phone 8

• Xbox Music is available on this OS. • It’s a digital music service that offers music through ad-supported streaming, subscription streaming, and

purchase through the Xbox Music Store. • Users have access to more than 30 million tracks from music groups like Universal, Sony BMG, EMI, and

Warner. • Microsoft also allows you to subscribe to the Xbox Music Pass, which lets you download an unlimited number

of songs.

Android 4.3

• Android 4.3 lets you load your music from other handhelds and computers without any kind of restrictions. • You can also purchase songs from Google Play, and use Play Music All Access, which lets you stream whatever audio you have stored in

the cloud.

Apps iOS 7• As of June 2013, the Apple Store offers 9,00,000 apps to its customers! • No other smartphone maker has been able to compete with Apple in this regard. • It’s also important to remember that most apps are first developed for iOS and then Android

and then maybe just maybe Windows Phone• One great update on the iOS 7 has been that apps will get automatically updated, without

you ever having to manually download updates.• If you still want to update apps manually, Apple gives you that option. Windows Phone 8 • The Windows Store has only 1,00,000 apps, and that too across different platforms. • Microsoft’s biggest drawback is its inability to provide a wide selection of applications for its

customers. • This OS has an Update All tab for its apps. Android 4.3 • Google’s Play Store offers lots of free apps, though their quality may not always be as great as

those offered on iOS.• Thanks to the launch of Play Music, Play Books, Play Movies, and Play Magazines,

downloading content has become a lot easier on Android than before. • Auto updating option is available too.

Which one should you get??

• If you want a phone that just works, and that has all the great user experience, app and game, accessory and services, customer support and iMore community benefits, then the iOS is for you. It's smaller than many competitors these days, doesn't have a hardware keyboard, and there's no giant camera bolted on, but it remains the single best phone in the world at what it does, and what it does it does very, very well.

• If you absolutely need a bigger screen from 4.3-inches all the way up to 6-inch "phablets and with some great features and tweak plus hardware you should get Android instead.

• Windows Phones come in a variety of screen sizes and price points, and all run Microsoft's elegant Metro interface and experience. The biggest reason to go with Windows Phone - literally - is the amazing camera available on the Lumia 1020 and other Lumia devices