I am developing an application for Android. I am not an experienced developer so I use the help of an SDK. There is a page that provided me with relevant information about mobile application development. It also shows code snippets that handle the physical buttons and the rotation features of the mobile devices. According to the page I am using the SDK and Adobe Flash Builder. In my opinion, as a novice developer, the information of the page (if you are interested: http://www.*****************/p_456-v...tion-voip.html) was really useful and understandable. I only meant to give an advice for other unexperienced developers and hope they will find it useful.