Angry Birds, one of the most successful apps out there, turned two over the weekend.

To celebrate those 'birds with attitude' and green little pigs, Rovio and Chillingo - the companies that created Angry Birds - have released a special Birthday 2.0.0 update that's available now through the Apple's iTunes Store.

With the update, look for new and exciting (or frustrating for some) levels along with some Birthday cakes added into the mix.

Chris Byatte, the co-founder and co-general manager at Chillingo, had this to say.

After two years, Angry Birds continues to delight fans and remain a steady fixture on the App Store’s top ten charts .This is quite a testament to the success indie developers can achieve with the right title, publishing partner and promotional support.

Hard core fans may also notice the addition of a new Orange Bird that can propel any object it touches by inflating.

 

Version 2.0.0 of the original Angry Birds game also unlocks every episode available. The game is available for the iPad, iPhone, iPod Touch and the Mac.

If you are having trouble completing the levels that you already have been playing, maybe these walkthroughs will help.

Can't get enough of those fair weathered fouls? Check out some of the cool Angry Birds swag available, just in time for the Holidays.