You might have heard of the fun physics/Rube Goldberg machine game Apparatus. It's actually pretty popular, and quite well-loved - over 800 reviews on the Android Market putting it at an average score of 4.5. For a game, especially, that's a very difficult feat to accomplish. It goes without saying then, that the developer of Apparatus is very concerned with customer feedback and providing support for his application.
Recently, he decided to distribute Apparatus through the Amazon Appstore.