Every day, the Amazon AppStore for Android is offering a free premium app to encourage a return to the AppStore more often. And today it's Angry Birds Seasons Ad-Free edition by Rovio Mobile. The app is free for all Amazon account holders in the US and customizes Rovio's insanely successful game with holiday themes. Currently, themes include Halloween, Christmas, Valentine’s Day and St Patrick’s Day. This premium version comes without any ads and is available free for one day only.