... developersSandberg Rollins The Business of Android Apps DevelopmentCompanioneBookAvailable The Business of Android Apps DevelopmentMaking and Marketing Apps that Succeed on Google Play, Amazon Appstore and ... how big the application is, as well as the complexity of the code, reliance on GUI tools, and ability of the developer.By the way, there are people who make it their business to program apps, ... availability of the source code. Internally, Android uses the Linux kernel.One of the great things about Android developer tools is they are free. This is one of the reasons why the operating...