During Apple’s WWDC 2011 keynote event Scott Forstall announced that iOS 5 brings 1500 new APIs for developers and more than 200 new features for users. However, only 10 were highlighted during the keynote presentation. iOS 5 finally brings “notification center” to iOS devices which allows users to manage all notifications by swiping downwards on the status bar.

iMessage, the tenth feature announced during the event turned out to be one of the most exciting features of the iOS. The new messages app supports iPhone, iPad and iPod touch and allows iOS device users to exchange messages using WiFi or 3G connection. iMessage directly competes with BlackBerry’s hugely popular BBM service. Apple’s new messaging app supports text and pictures messages and you can share videos and contacts too.

For iPhone users iMessage cleverly integrates with the existing messages app. When you start typing the recipients name the app contacts Apple’s server to determine if the user has iMessage and if the other device is running iOS 5 then the send button on your device will turn blue which indicates that the message won’t be billed by your carrier. However, if the recipients device does not support iMessage then the send button turns green which indicates that the message will be sent as a normal SMS / MMS and will be billed by the carrier.

iMessage also supports some of the more advanced features like group messages, delivery and read reports and your entire conversation is always in sync across all your iDevices.

If most of your friends or family members use iPhones, iPads or iPod touches then iMessage would certainly become the primary way to text each other. It’s taken Apple five major software releases to finally come up with a universal messaging application for iOS device users. Forstall was confident about the reliability of the company’s new service as it is built on Apple’s existing robust push notification system.

Are you excited about iMessage for iPhone, iPod touch and iPad? Let us know what you think in the comments below.