Strange how information sometimes filters through. The Amazon Appstore for example. Amazon has yet to give an official opening date, but Rovio, makers of the forthcoming Angry Birds Rio, claim it will be available exclusively at the Amazon Appstore on 22nd March. So we can presume the store opens for business either on that day or before. No matter which way you look at it, the Appstore will be open this time next week.According to TechRadar, Rovio has announced through Twitter and its blog that it will be launching Angry Birds Rio, exclusively through the Amazon Appstore, with that date of 22nd March. It's a paid-for app (as opposed to being funded by ads), even though the game is a tie-in / promotion for the upcoming Rio animated film from Twentieth Century Fox. Angry Birds Rio will offer 60 new levels, featuring birds from the animated movie.The Amazon Appstore is also offering paid (and ad-free) versions of Angry Birds and Angry Birds Seasons, the first time Android users will be able to play the apps ad-free. Plenty of other apps too we presume (this isn't the Angry Birds store, after all), but details of those are so far being kept under wraps. However, Rovio CEO Mikael Hed does touch on what to expect.'The openness of the Android platform works for the benefit of consumers and developers alike. It has been delightful to team up with Amazon to bring the Angry Birds franchise to this great new application marketplace.'