Apple Inc. provides updates to the iOS operating system for the iPhone, iPad, and iPod Touch through iTunes, and since iOS 5.0, also through over-the-air software updates. With the June 6, 2011 announcement of iOS 5.0, a USB connection to iTunes is no longer needed to activate iOS devices; data synchronization can happen automatically and wirelessly through Apple's iCloud service. The most recent major update, iOS 7, sees the addition of many new features, including a new flat theme, AirDrop support, and Control Center.
Apple's iOS did not have an official name until the release of the iPhone software development kit (iPhone SDK) on March 6, 2008. Before then, Apple marketing literature simply stated that their iPhone runs a version of "OS X", a reference to iOS' parent operating system. When introduced, it was named iPhone OS. It was renamed iOS on June 7, 2010, as iPhone was no longer the only device to run iOS. Apple licensed the "iOS" trademark from Cisco.
On June 29, 2007, Apple released the first version of what became iOS – concurrently with the first iPhone. The final 1.x series release was 1.1.5, released shortly before version 2.0.
July 11, 2008 saw the public release of iPhone OS 2.0, with upgrades through version 2.2.1 made available.
June 17, 2009 was the release date for iPhone OS 3.0. It was updated through (and including) version 3.1.3 (release date February 2, 2010). The first generation iPod Touch and iPhone have iPhone OS 3.1.3 as their newest available version. The iPad was introduced with iPhone OS 3.2, later updated to 3.2.2, a version made specifically for the iPad.
On June 21, 2010, iOS 4.0 was released to the public and was made available only to the iPod Touch and iPhone. iOS 4.0 was announced to have over 1500 new APIs for developers, with the highly anticipated multitasking feature. The iPod Touch (2nd generation) and iPhone 3G have iOS 4.2.1 as the final version available. Nevertheless, many features are not available for the iPhone 3G or iPod touch 2nd generation, such as multitasking and home screen backgrounds. iOS 4.2 is the first version to bring major feature parity to the iPhone and iPad. The release of the CDMA iPhone for Verizon Wireless saw a branching of iOS. The 4.2 version sequence continued for the CDMA phone while 4.3 was released for all other products.
iOS 5 had only three minor additions, 5.0.1, 5.1, and 5.1.1, which were all provided as an OTA software update.
Apple concurrently provides the same version of iOS for the comparable model of iPhone and iPod touch, usually devices released in the same calendar year. iPhone users receive all software updates for free, while iPod Touch users paid for the 2.0 and 3.0 major software updates. As of iOS 4.0, Apple no longer charges for iPod Touch updates.
As of October 23, 2011, two versions of iOS were never released. iOS 1.2, which after the first beta was replaced by a 2.0 version number; the second beta was called 2.0b2 instead of 1.2b2. The other was iOS 4.2, replaced with 4.2.1 due to a Wi-Fi bug in 4.2 beta 3, causing Apple to release 2 more golden masters (4.2 GM and 4.2.1 GM).
First iteration of Apple's touch-centric mobile operating system. No official name given on its initial release; Apple marketing literature simply stating the iPhone runs a version of Apple's desktop operating system, OS X. On March 6, 2008, with the release of the iPhone software development kit (iPhone SDK), Apple named it iPhone OS (they went on to rename it "iOS" on June 7, 2010).
Table of versions: iPhone OS 1.x – portable iOS devices
Commonly called the iPhone "January '08 Update" and January Software Upgrade by Apple.
Free update for iPhone; $19.95 in iTunes for the iPod Touch.
Mail, Maps, Stocks, Weather and Notes apps for iPod Touch.
Recent calls contact details now show most recent call times.
Google Maps on iPhone gains the 'Locate Me' feature which can determine the phone's approximate location, using a combination of cellular triangulation and Wi-Fi data from Skyhook Wireless; also adds hybrid map support and the 'Drop Pin' feature.
Icons on the home screen can be rearranged and placed on multiple home screens (up to nine).
iTunes gift cards can be redeemed on the iTunes Store.
Movies downloaded through iTunes have chapter support.
Music has lyrics-support feature.
Web Clips can be added to (and subsequently removed from) the home screen.
SMS messages can be sent to multiple contacts using messages.
SMS storage capacity increased from 1,000 to 75,000 messages.
Default GmailIMAP setup for new accounts (previously was defaulted as POP3).
The clock timer now remembers the last used options (bug fix).
Incoming SMS messages now prompts the user to "Close" or "Reply" (previously "Ignore" or "Reply"). Pressing either option now marks the message as "seen".
Labels for contact data can now be deleted.
Applications on the phone no longer run as root; they run as the user "mobile" instead.
Ability to listen to music through a Bluetooth headset by going to the voicemail and choosing "Bluetooth" as the audio source no longer works (still works as long as phone is not locked or voicemail screen is active).
2.0, the second major release of the iOS, became available with the release of the iPhone 3G. Devices running 1.x are upgradable to this version. This version of the OS introduces the App Store, making third-party applications available to the iPhone and iPod Touch.
Table of versions: iPhone OS 2.x – portable iOS devices
Free for iPod Touch users who have upgraded to iOS 2.0.
Initial release on iPod Touch (2nd generation) (as 2.1.1).
Companion changes in/with iTunes 8 for this release
Displays capacity and used space of information on iPhone.
Dramatically reduced time to back up to iTunes.
Does not remove all media after restore.
Faster firmware installation and data sync.
Application updates downloaded from iTunes have new finder naming convention.
Bug fixes, performance enhancements
Security fix to prevent from bypassing the double home button exploit.
Fixed bugs causing hangs and crashes for users with lots of third party applications.
Faster installation and updating of 3rd party applications.
Updating applications keeps their icons in place on the home screen.
Improvements to Mail stability.
Improved email reliability, notably fetching email from POP and Exchange accounts.
Faster loading and searching of contacts.
Auto-correct now appears above the text instead of below (fixing a usability problem people were having where auto-correct would appear above the first row of keys).
Smoother browsing in Safari, particularly when scrolling up/down on a web page.
Significantly better battery life for most users.
Decrease in call set-up failures and dropped calls.
Improved accuracy of the 3G signal strength display.
Some Bluetooth headsets which didn't originally work with visual voicemail on previous firmware versions have been reported to be working on 2.1.
The 12/24 hour clock which has been available in previous versions is now usable to UK iPhone users.
Improved way of creating the "Application Map" on reboot fixes the "ALoD" issue.
Third-party application settings are loaded after loading the main Settings.
With the UK English keyboard setting, when entering URLs, holding down the '.com' button would bring up shortcuts to other TLDs, but for some reason it would drop '.net' to make room for '.co.uk'. 2.1 adds '.net' for the UK English keyboard.
Apple have fixed the grammar in the App Store when all apps up to date. Before 2.1, the update page would display the text "All Apps Are Up-To-Date." (hyphenated with a period). The update page now displays the text "All Apps Are Up to Date".
Double tapping (the standard gesture for zooming) didn't work in prior firmware versions in the Mail application. The only way to zoom into content (e.g. a HTML attachment/web page) was to use the 'pinch' method. 2.1 now adds the functionality of double tapping to zoom in the Mail application.
Triple-click on the control button of headphones now jumps music to previous track played.
SMS app can alert up to two additional times if you don’t acknowledge an incoming text message (will play the alert sound/vibrate again after a period of time as if a new message just came in).
When receiving a text message, it used to display "Sender — Text Message" when the message preview was off (e.g. "Pete — Text Message"). Now just displays "New Text Message".
Update supporting languages.
Option to wipe data after ten failed passcode attempts (after 5 attempts, the device will disable itself for 1 minute. After the 6th attempt, it will disable itself for 5 minutes. In the 10th attempt, it will wipe all data).
The camera can now be turned off within the restrictions page.
When taking a screen-shot of your phone, there is now the camera shutter noise.
Pause apps by clicking the icon while it downloads/installs.
Updated apps now keep their original position in the Home Screen.
iPod volume/application volume setting is now independent of the phone ringer volume setting.
iPhone never gets locked when placed in dock and playing music.
New application features
Genius playlist creation.
More information provided within iPod Music lists (artist and album are now shown below song title when selecting music in addition to remaining time on podcasts).
More information is provided for audiobooks, such as displaying time left in active audiobook.
New podcasts & videos had "filled" blue bubbles next to them to indicate that they were new, now if you have "half-played" a podcast or video, it will include a half filled blue bubble.
Sound from iPod now fades out if you start syncing device with iTunes.
Options to load & display earlier text message in a conversation.
EXIF data information now remains on photos/pictures when emailed from your iPhone. Sites such as Flickr are now able to show geotag and other information.
When location services is switched off in the Settings menu, the Maps application reminds you to manually turn it back on from the Settings menu when using GPS. Originally, you would have the option to turn it on when the notification appeared.
Bookmarked home screen apps open in full screen.
iPod Touch only
Settings for individual speaker sounds. Sounds can no longer be turned off en masse. All sounds must be turned off individually to mute sounds.
3.0 became available with the iPhone 3GS. It was released on June 17, 2009. This release added features such as copy and paste, and MMS. Not all features were available on the original iPhone. Devices running 2.x were upgradeable to this firmware.
Table of versions: iPhone OS 3.x – portable iOS devices
Features iPhone users got in 2.2 now added for the iPod Touch (e.g. Google Street View, public transit and walking directions, display address of dropped pin, share location via email, and cache of recent locations). Changed behavior when routing directions and showing steps.
Landscape mode that enabled viewing detailed price and change information by dragging one or two fingers across the full-screen chart.
Metadata display for detailed information about the symbol, including full company/fund name, market capitalisation, price to earning ratio, dividend yield, and statistics about the day and year price range.
Table of news stories from various internet sources related to the selected symbol.
Can now log into account.
View subscriptions, Favorites, My Videos, History, and Playlists
Comment on videos, rate videos
Recent Calls now show more details (call length, etc.).
Ability to change/set "own number" (my number) in the SIM card. Will be displayed in the Contacts list and iTunes, as well as possibly used for MMS identification.
Holding the home button will no longer force quit an unresponsive application. To force quit an application in 3.0 hold the sleep/wake button until the red power off slider appears. Then hold down the home button to quit the unresponsive application.
Screen captures are no longer numbered separately from photos taken with the camera application; all new images in the camera roll now use a common numbering sequence.
On iPod Touch (2nd generation) the Voice Memos app now successfully records audio if you plug your microphone after you have started the application.
Numbers inside Notes have more options when tap and hold is triggered: Call, Text Message, Create New Contact, Add to Existing Contact.
Voice control over Bluetooth is now available, allowing users to initiate calls and control music playback via Bluetooth headsets (however, voice control while plugged into car audio systems no longer works).
iOS 4 was made available to the public for the iPhone and iPod Touch on June 21, 2010, and is the first release to be renamed to simply "iOS". This is the first major iOS release to drop support for some devices. It is also the first major iOS release that iPod Touch users do not have to pay for.
The iPhone 3G and iPod Touch (2nd generation) have limited features, including lack of multitasking capabilities and the ability to set a home screen wallpaper. While the iPhone 4, iPhone 3GS, iPod Touch (3rd & 4th generation) have all features enabled, such as multitasking. The iPhone and iPod Touch (1st generation) cannot run iOS 4.0 and above.
iOS 4.2.1, released November 22, 2010, added iPad compatibility. It also was the last version to support iPhone 3G and iPod Touch (2nd generation, MB & MC model).
Ability to cancel and delete an app which is currently downloading. Before iOS 4.3, it was only possible to delete an app which had already downloaded.
Stream from an iTunes library to iOS using Home Sharing.
In-app purchases always ask for a password, even if one has previously been entered.
Internal system clock gets network time updated more frequently via NITZ (part of the official GSM standard since phase 2+ release 96) and gives a more accurate time for the device, it updates about every five days.
Personal Hotspot feature (Wi-Fihotspot with up to 5 simultaneous devices (Wi-Fi hotspot iPhone 4 only)) on supported carriers.
Ability to set amount of times a text tone repeats (up to 10 times).
In field test mode refresh button has been removed & updated information has been displayed in bottom of the screen (it updates every 4–6 seconds).
Slideshow options moved to Photos app.
New look for taking a picture for a Contact.
When receiving a text message, the iPhone now vibrates 2 times.
All notifications concentrated to Notification Center: swipe downwards from the status bar to open it. Notification center shows a list of all notifications and widgets (widgets available only on iPhone & iPod Touch).
Notification order can be arranged.
Choose Notification Type: Banner notifications, the classic pop-up notifications, or no notification at all (selectable on an app-by-app basis).
Notification list on lock screen. Swipe an icon to unlock and go to the specific notification.
Notifications announcing earthquakes with 2 minutes (only in Japan).
Messaging between all iOS devices running iOS 5 through Wi-Fi or 3G. Allows to send text, photos, videos, contacts, and locations.
All iMessages and conversations will be synced between all iOS devices linked under a single Apple ID. You can start a conversation on one device and continue it on another.
Can message between multiple people simultaneously (group messaging).
Shows when other person(s) is typing.
Optional read receipts (enable in Settings).
Animated GIF image support for iMessage.
Ability to set how many times an alert will be shown when a new message is received (ranges from once to ten times).
The name of the person that responds appears in small light blue text directly above the response when SMS is sent to a group.
Slight redesign for text messages. Font & time-stamp layout.
Hide keyboard; hidden by downwards scrolling in message screen (after being used to type a message). Unhidden again by tapping in text entry field.
Can now create, rename, and delete calendars right on the device.
Tap and hold or double-tap to create a new event.
Tap and hold in "all-day events" to create a new all-day event.
Drag appointments to a new time slot.
Drag handles to change start and end times.
Creating new Event, now an "Invitees" field; takes to screen for multiple email address entry, emails sent to all invitees once event is saved.
Invitee can “Accept”/“Decline”/“Maybe”; reply sent to iCloud servers then reflected for all invitees to see.
Calendar event on device lists those invitees accepting event.
All users on iOS 5.x devices get notification when event is nearing.
Ability to specify a time zone to events.
Ability to add URLs to events.
Current time on Calendar if in landscape mode.
Navigate in day view by swiping.
Event attachments can now be viewed directly in the app.
Share calendars through iCloud with friends and family. Edits made by subscribers to that calendar are updated and pushed to other subscribers of that calendar (can be disabled by the creator of the calendar and locked so others cannot make edits).
Japanese or Buddhist calendars support.
Rich text formatting (bold, italics, and underline).
Ability to mark multiple mail items as read.
Ability to flag emails.
Draggable mail address in the recipients field.
Alert if the subject line is blank.
Search now includes body of messages.
Delete mails while in Airplane mode.
Exchange Activesync Email can now be deleted offline.
Can create new email folders.
Ability to show 1000 recent messages; 25 message option removed.
Ability to create additional @me.com email address within the Mail settings.
Ability to increase quote level in Mail settings.
New and updated tiny icons on Mail for Windows Live Mail, Gmail, Exchange, etc.
Hotmail accounts now have new icons and folders.
While reading an email you can swipe right to open a list of messages and swipe left to bring back the open email message again.
If you have multiple email accounts configured in Mail.app, swipe left or right from one’s mailboxes folder list, it will take you to another account’s mailboxes.
Support for three popular Chinese email services: Tencent’s QQ Mail, and Netease’s 163.com & 126.com mail inboxes.
Built-in basic photo editing: crop, red-eye, auto-enhance and rotate photos.
Ability to create and edit local photo albums folders (only those that aren't synced with iTunes).
Ability to sync pictures taken on one iOS device automatically with other iOS 5 devices using Photo Stream.
Ability to select all when adding pictures to an album.
Slight re-design for video time-line under Photos app.
Safari Reader: new "Reader" icon appears in address bar if Safari detects a webpage article, removing need to click-through to each page. Scrollable window sheet appears over current webpage showing all article pages together separated by page breaks, removing ads and page clutter.
Ability to change font size in reader mode.
Reading List: a new area of the bookmarks window has been added, purposed for pages you might want to read later. New pages can be added from a new option in the action menu or when long-pressing on a link.
Items from the Reading List can be synced to iCloud to be pushed to all of your other iOS devices.
Safari bookmarks can be synced to iCloud.
Ability to open pages in background or in new page (change in Settings).
Ability to replace a word with a word from a list of similarly spelled words spellings when typing in a text box on a web page.
Private Browsing; interface colours change from blue to black (change in Settings).
Ability to remove custom website data.
CSS fixed position support.
Slight fade out at end of long URLs (instead of ellipses) in the address bar.
iOS 6 was announced and previewed on June 11, 2012 during Apple Worldwide Developers Conference (WWDC) 2012, and its release was stated as Fall 2012. Following the pattern of previous iOS releases, some older devices were no longer supported, specifically the iPod Touch (3rd generation), and the iPad (1st generation). Supported devices include the iPhone 3GS and later; the iPod Touch (4th generation) and later; and the iPad 2 and later.
On September 12, 2012 at San Francisco's Yerba Buena Center for the Arts, among other items unveiled, Apple announced three iOS-related items: the next generation iPhone 5, the redesigned iPod Touch (5th generation), and the announcement of the release of iOS 6.0 the following week.
iOS 6 was released to the public on September 19, 2012, through iTunes and over-the-air updates.
iOS 6.1.3 is the final release supported for the iPhone 3GS and iOS 6.1.5 for the iPod Touch (4th Generation).
Siri now available on iPad (3rd, 4th generation and Mini) and iPod Touch (5th generation).
Additional country and language support for Canada (English and Canadian French), China (Mandarin), Hong Kong (Cantonese), Italy (Italian), Korea (Korean), Mexico (Spanish), Spain (Spanish), Switzerland (Italian, French, German), Taiwan (Mandarin), US (Spanish).
Message previews can now be toggled on/off for alerts.
Calendar now shows the current date in the title bar.
Shows ending times for Calendar events.
Added "Do Not Disturb" for Notifications. (See Settings, below, for more information)
Shared Photo Streams. Photos can be shared with other contacts. Photos shared can be commented on and liked. Notifications are enabled for when a contact shares a photo with the user.
New sharing menu, using new icons.
Constantly shows a button to create new Albums.
Sharing menu has options for Twitter, Facebook, Weibo (when Chinese keyboard is enabled), as well as Copy, Slideshow, AirPlay, Use as Wallpaper, & Print.
Videos can be uploaded to Youku and Tudou when the Chinese keyboard is enabled.
New streamlined UI with white and black themes.
Late Night Mode equaliser.
"Bluetooth" moved to top of Settings list.
Added "Do Not Disturb" mode, allowing users to avoid calls and notifications unless calling parties are on the user's Favorites group. A crescent moon icon will appear in the status bar when enabled. Has no effect when the screen is on.
Fullscreen landscape mode (for iPhone and iPod Touch).
iCloud tab syncing across iOS devices and Macs.
Offline Reading List caches the user's Reading List for later use, even when not connected to the Internet (not available for iPhone 3GS and iPod Touch (4th generation)).
Smart App Banners: Banners on mobile webpages prompt users to download the website's native App Store counterpart in the App Store.
Apps in search results.
Support for photo upload via Camera Roll to web forms with <input type="file"> elements.
Support for up to 24 open tabs on iPad (up from previous limit of 9).
Bookmarks window now displays tabs along the bottom of the window for switching between viewing "Bookmarks", "History" and "Reading List"; previously was just listed all in one source list (iPad 2 and later only).
Bookmarks button changes to Reading List icon with a progress bar when updating the Reading List for offline use (iPad 2 and later only).
Long press the "Back" or "Forward" button to reveal the browsing history (for iPhone 3GS and later, iPod Touch (4th generation) and later. Previously only available for iPad since iOS 5.x).
New music controls on lock screen when you double-press home button.
Siri can now purchase movie tickets via Fandango (USA only).
LTE now works with several European, African, Asian and American carriers.
Individual songs can once again be downloaded or deleted when using iTunes Match.
An empty Passbook will automatically add a sample pass explaining passbook functionality. The pass text changes slightly for users in British English speaking countries, changing “movie tickets” to “cinema tickets” in the first sentence, and “theaters” to “cinemas” in the last sentence.
Reset Advertising Identifier button now works.
New cellular data option for iTunes (it is available from iOS 6.0).
When setting up an iOS device for the first time with iCloud, it will now ask you to confirm your Apple ID password for FaceTime and iMessages. It will also ask you to confirm how you'd like people to reach you, and tells you that you can change these settings at any time later on.
Fixed an iPhone 5 bug that prevented the phone from reconnecting to the cellular network when it lost connection for an extended amount of time.
"Accessory attached" splashscreen removed. Bi-directional control now possible.
Fixed a Bluetooth A2DP trigger delay - the beginning of the audio stream cut off (e.g. when navigating turn-by-turn, you heard "HT in .5 miles" instead of "TURN RIGHT in .5 miles" in your A2DP headset/speakers)
Fixes an issue that causes FaceTime calls to fail for some users on the iPod Touch 4th generation. (This update does not include bug improvements that recently occurred in iOS 6 unlike iOS 7.0.4 which included bug fixes that occurred during iOS 7)
Flat design and move away from skeuomorphism in general (exceptions exist - for a move towards more skeuomorphism, see for example the Countdown with a new skeuomorphic 3D animation of a spinning wheel).
On October 23, 2011, Apple TV (2nd generation) software was updated to version 4.4 bringing Photo Stream, Airplay mirroring (from iPhone 4S & iPad 2, later iPad (3rd generation)), NHL, Wall Street Journal, slideshow themes and Netflix subtitles. Contrary to rumors and code found in iOS 5, the release did not bring support for Bluetooth or apps to the Apple TV 2.
Table of versions: iOS 5.x – Apple TV (2nd generation) onwards
On September 24, 2012, Apple TV (2nd generation) onwards received the iOS 6.0 software update, with version 5.1's main features being Shared Photo Streams, iTunes account switching, better AirPlay functionality, and Trailers searching, among other smaller improvements.
Table of versions: iOS 6.x – Apple TV (2nd generation) onwards
Shared Photo Streams: Accept invitations for Shared Photo Streams, browse photos and comments, and receive notifications of new content.
AirPlay: Send audio content from Apple TV to AirPlay-enabled speakers/devices (including AirPort Express and other Apple TVs). Also includes the ability to require an onscreen code to use AirPlay with your Apple TV.
iTunes account switching: Save multiple iTunes accounts and switch quickly between them.
Trailers: Search for movie trailers. In the United States, see show times for local theaters.
Screen savers: New Cascade, Shrinking Tiles, and Sliding Panels screen savers.
Main menu: Reorder icons on the second page by holding down the select button on the remote.
Subtitles: SDH support for the deaf and hard-of-hearing as well as improvements to viewing and selecting subtitles.
Network configuration: Support for setting up advanced network options using configuration profiles.
Stability and performance: Includes general performance and stability improvements.
The Alarm feature of the built in Clock app in the iPhone and iPod Touch has been plagued by major bugs in all versions of iOS 4. The first bug noticed was the "DST bug" which was first seen when some countries switched to/from daylight saving time from/to standard time in October/November 2010. It caused recurring alarms to start going off an hour too early or late. Apple promised the bug would be fixed in iOS 4.2 but according to some reports it still exists even in iOS 4.3.1.
The second alarm clock bug discovered was the "New Year's Day bug" which showed up on January 1, 2011 as well as January 1, 2012. It caused non-recurring alarms not to go off at all. However two days after each New Year's Day, on January 3, 2011, they "magically" started working again. This bug was seemingly fixed in iOS 4.3.
Apple has confirmed that several battery life bugs are negatively affecting battery life in iOS 5. They attempted to fix these bugs with iOS 5.0.1 but the problem still remained.
The launch of the iOS 5 update on October 12, 2011 (including iOS 5.0.1 released on November 10, 2011) led many users to report a major bug causing the device to lose Wi-Fi access. This problem has supposedly been fixed with the release of iOS 5.1.1
Some users of the iPhone 4S and iPad reported issues with the SIM card in the initial release of iOS 5, and even though Apple attempted to fix these issues in version 5.0.1 build 9A406 (for iPhone 4S only), they still remain.
Some users of the iPhone 4/4S reported issues with having echo problems during phone call in the initial release of iOS 5, which causes echoes to appear randomly during phone calls made through earphones. The other party in the call is generally unable to hear the conversation due to this problem. The owners reported a "fix" that is to switch to speaker mode when echo happens then switch back (turn speaker off), which would get rid of the echo temporarily, but it might happen again within the same phone call. It is unclear that whether Apple attempted to fix this issue in version 5.0.1, but for many users this problem still remains after updating to 5.0.1. It appears that the new noise-cancelling microphone/technology might be the reason behind this bug. Apple has since released version 5.1.1 in an attempt to fix the problem.
Apple has admitted that there were several bugs in the mapping app on iOS 6, with cities in the wrong location, some places being missed off altogether, some places misnamed and places of interest in the sea.
Many users report a problem with Bluetooth audio streaming to a range of compatible devices. The sound cuts out every now and then for no apparent reason. As of October 2012[update], no solution has been provided by Apple.
Location-based reminders do not work for iPads, even though they were promised to work on cellular enabled devices.
A lot of users reporting problems with the iPhone 5 not reconnecting to the cellular network, when having lost connection for more than 5 minutes and staying at no service. As of December 2012[update], no solution has been provided by Apple and the problem was not solved with the 6.0.1 iOS release.
Many iPhone users experienced a bug with the Do Not Disturb feature when the calendar changed from 2012 to 2013. The feature would be left on past the scheduled time set by the user, allowing texts, notifications, and alarm settings to be missed. The bug was caused by a difference in formatting in the ISO calendar system versus the Gregorian calendar system. Apple did not offer a quick software update for the bug, instead saying that the bug would fix itself on January 7, 2013.
From iOS 6.1, new major bugs have been identified. The first was addressed when iOS 6.1.1 was released that "fixes an issue that could impact cellular performance and reliability for iPhone 4S".
Another bug causes issues when iOS devices connect to a Microsoft Exchange server to retrieve email, resulting in message "mailbox server resources are consumed, log growth becomes excessive, memory and CPU use may increase significantly, and server performance is affected". Microsoft have suggested several workarounds, and Apple responded with a KnowledgeBase article describing the cause of the bug and a suggested temporary workaround, promising a fix in the near future, which was then fixed with release of iOS 6.1.2.
On iPhones, another bug found in 6.1 allowing bypassing the lock screen's passcode to temporarily gain full access to the Phone app, by performing a specific sequence of actions on the phone that remained unfixed, with Apple acknowledging the bug and then addressed with release of iOS 6.1.3.
iPhone 5 users experienced dropped calls during the release of iOS 6.1.3 when there was an issue with the audio speaker profile. This also caused issues with many voice-over commands, including Siri, to get different results than expected or fail easily. Apple fixed this bug with the release of iOS 6.1.4 to update the audio speaker profile so users would get better results.
Shortly when Apple released iOS 7, some users including iPhone 3GS users were unable to upgrade to the latest software due to the RAM capabilities. However, a FaceTime issue occurred in iOS 6.1.3 when video calls were failing for some users on the iPod Touch 4th generation. Apple then fixed this bug with the release of iOS 6.1.5 for the iPod Touch 4th generation on November 14, 2013, along with iOS 7.0.4 for iOS 7 devices for the same purpose. iOS 7.0.4 included bug fixes that occurred during the release of iOS 7 whereas iOS 6.1.5 did not include the bug improvements that appeared on iOS 6 when Apple did not realize, noticeably since iOS 5, that the echo bug has still occurred.
People are able to bypass the lockscreen. This flaw was discovered within hours of it becoming publicly available. The exploit is only able to be done on the iPhone 4S and 5 with the 5S and 5C safe from this bug. The access is caused by the ability to use the control center via the lock screen, this feature is able to be turned off.
Users complained about dizziness and vertigo-like symptoms when using this operating system.“ 
Creation of CardDAV Accounts not working
Creating a CardDAV Account contains a bug that needs manual fixing of the CardDAV-Server-URL.
Battery drain problems
Issues with battery draining even though sleeping. 
Issues with video-calling and connection errors. (See iOS 6.x)
^Gibbs, Samuel (September 22, 2013). "Apple says it's working on fix for iOS 7 lockscreen bypass flaw". theguardian.com. Guardian News and Media. Archived from the original on September 22, 2013. Retrieved September 22, 2013. "Embarrassing discovery comes within hours of release of new software and exploits Control Center feature to hack into photos, texts and Facebook content"