If you have an iPhone 3G, or 3GS, or second- or third- generation iPod touch, then there's an upgrade waiting for you, the next time you connect your gadget with iTunes.

The upgrade, called the iOS 4, is free of cost and is the latest version of the mobile operating system software, previously known as iPhone Operating System. It's chock-a-block of highly developed attributes and is sure to make your iPhone or iPod touch more advanced than earlier. If you have the latest iPhone 4, it is already pre-loaded with iOS 4.

Maybe, the largest enhancement is multitasking, which allows third-party apps to operate in the backdrop and carry on to work, while you're making use of other apps. That means, you can now listen to music played by apps like Pandora, whilst you go through your photograph album. Or you can get calls via VoIP services like Skype, even if Skype app is not operating.

The fresh consumer interface for multitasking is mainly engaging. Some time ago, if you desired to restart an app, which was on your fifth or sixth home screen, you'd have to scroll through the screen five or six times, even if you have utilized that app few minutes back. The new excellent multitasking interface makes it quick and simple to open that app with just two finger touches.