Rovio have been working on a little project, well actually it is a big undertaking, which will have all their Angry Birds game sync up to users devices. What does this mean? It means that if you buy a new Android device, install Angry Birds, normally you would have to start over again and finish levels you've already completed.
What the syncing up will do is bring your completed levels over to your new device which mean you won't have to redo all those levels again when you get a new Android device. If you come from iOS and buy an Android device, the plan is to have all your completed levels come over to your new device, even if it is a new platform. This works both way should you decide to buy an iPhone and are coming from an Android device.
The plan is to have this new sync feature enabled across all platforms the Angry Bird games are on, not just Android and iOS. So when will this be available? Rovio has stated it will be out sometime 'before Summer'. It will definitely be nice not having to start over every time we install Angry Birds on a new device.