Angry Birds celebrated its 2nd birthday yesterday and released a free content update. “Version 2.0″ of both Angry  Birds  is available for iPhone, and  Angry  Birds HD for iPad.

If you haven’t yet purchased either app, you can grab Angry Birds for £0.69 and Angry Birds HD for £2.99 . However, if you already own both Angry Birds applications, the updates are free to download.

So whats new in version 2.0  - The Angry Birds are celebrating their 2nd birthday, but the pigs are crashing the party and it’s up to you to save it!

Satisfy your sweet tooth with 15 brand new birthday cake levels!

Celebrate 300 LEVELS of Angry Birds!

Party with the amazing expandable orange bird!

There are new menus & graphics to take a look at and also special birthday achievements make this update a treat!