Apple wil release its revamped mobile operating system, iOS 6 for free download form 19 September 2012.

Following the release, customers with iPhone 3GS, iPhone 4, iPhone 4S, fourth-generation iPod Touch, iPad 2 or third-generation iPad can upgrade their devoces with iOS 6 for free, the iPhone maker said.

According to Apple, iOS 6 will allow Notification Center to post to Twitter as well as Facebook and offers Safari Web browser with new fullscreen landscape mode.

The new OS’s iCloud Tabs feature will allow iCloud to list the opened Safari tabs among devices operating the iOS 6 or OS X 10.8 Mountain Lion.

Apple said that the VIP feature in the Apple Mail in Mountain Lion will redirect the user to the iOS 6 Mail app, further allowing the VIP lists to be synced between devices.

Features of the new OS also include Facebook integration for Contacts and Calendar in addition to Passbook, which will allow users to attain all required passes at one place.

The new Siri features, comprising support for more languages, easy access to restaurant recommendations and movie listings, will launch apps via voice.

Apple also revealed that iOS also features redesigned iTunes Store, App Store, and iBookstore apps which facilitates navigation.