iOS 5 the much anticipated major update to Apple’s mobile operating system, which was unveiled at Apple Worldwide Developers Conference (WWDC) 2011, boasts of beefy new features including News Stand, Reminders, iMessages and Delta Updates that will help the next generation (dubbed iPhone 5) steal a march over rival Android.

Apple unabashedly claimed on Monday that the iOS is the No.1 mobile OS with 44 percent market share. The company dubbed iOS 5 release a major and “incredible” release for developers and customers alike.

The technology giant said iOS 5 comes with 1500 new APIs and 200 new features but walked the audience through top 10 features that promise to help iPhone 5 steal a march over rival Android:

1. Notifications – Criticizing the current notification systems available on smartphones, Apple introduced a new notification system in iOS 5 that will aggregate all notifications. The new Notification Center can be accessed by swiping down from the status bar at the top of the screen.
The new Notification Center is a single place to combine all notifications. Apple said the new push notifications have been “scaled beautifully” and are no longer annoying or obtrusive. The notifications will be displayed on the lock screen together with stock and weather alerts. Now, when a notification appears in a lock screen, tapping the notification will automatically open the related app. The UI also looks radically cool thanks to nifty animation effects.

2. News Stand - The new News Stand app that comes with iOS 5 will complement the existing iBooks. Though similar to iBooks, News Stand will be dedicated to magazines and newspapers. Automatic downloads are possible. The newspapers and magazines can also be read offline.

3. Twitter integration – As rumored, Apple has ditched Facebook to integrate Twitter into iOS. There will be a single sign-in for Twitter and all related apps. Twitter UI has been integrated with the camera as well as Photos and Maps and Safari. Contacts have also been integrated with Twitter.

4. Mobile Safari – Apple boasts that 2/3 of all mobile web browsing is done on Safari. iOS 5 makes Safari look even better. The web browser now has several new features including tabbed browsing (switching between tabs is “lighting fast”) and the Safari reader feature that allows the users to quickly save stories for later reading in the Reading List. The Reading List can be synced across multiple devices.
The Mobile Safari also enables users to email story content together with link and if the user so desires, the Safari Reader will get rid of reviews, ads and other unnecessary content on the page to enable user to dive right into essential stuff.

5. Reminders – The new Reminders app now makes it possible to maintain multiple list and save them with dates to alert you. The Reminders has geolocation capabilities i.e. it can send Reminders to user based on user location.

6. Camera – The camera can now be accessed faster as it gets a shortcut on the lock screen. To access, double tap the home button and then tap the camera icon. For taking photos, simply tap the volume up button. Other new camera features include crop and rotate, edit, red eye reduction, auto focus and auto exposure, and auto enhance (using iPhoto).

7. Mail – The new Mail feature in iOS 5 has seen some significant changes. It now comes with rich text formatting message flagging and draggable addresses. Now entire messages can also be searched.
There are also keyboard enhancements: now it is possible to drag the keyboard up, split the keyboard (to make it more ergonomic). The size of the keyboard can also be reduced to facilitate thumb-typing.

8. PC free function – iOS 5 is “PC free” i.e. now there is no need to hook up mobile Apple devices with PC to access iTunes. iOS updates are now possible over the air. iTunes library can also be synced wirelessly via Wi-Fi. iTunes sync is now automatic and possible even while an iOS device is being charged.
Delta updates are also available i.e. software updates are now over the air and you can download only the necessary update and not the entire app/software.

9. Game Center – According to Apple, iOS is the “most popular gaming platform on the planet” thanks to 50 million unique game center users. The Game Center function has now been enhanced to include friend recommendations and profile avatars and friend recommendations. Now it is possible to purchase and download new games within Game Center.

10. iMessage – iMessage is perhaps the most important feature in iOS 5. The iMessage, which is only available to iOS users allows sending text and multimedia messages over Wi-Fi and 3G. It comes with read and delivery receipts and real time typing indication. The iMessages can be pushed out to all iOS devices a user owns, thereby allowing, for instance, the user to start a conversation in iPhone and continue the same on an iPad right where it was left off.

 The developer seed of iOS 5 was made available on Monday. The customers will get to see iOS 5 this fall.