I am developing an own application for Android. I am only a beginner developer and I use an SDK to complete my project. On the Internet I came across a page that deals with application development. The page also offers code snippets that handle the physical buttons and the rotation features of the mobile devices. As the instructions say on the page I am using the SDK and Adobe Flash Builder. As a beginner developer I found the information provided by the page (if you are interested: http://www.voip-sip-sdk.com/p_456-voip-android-integration-voip.html
) to be really clear and understandable. I belive that other not so experienced developers might also find it useful. I only meant to give an advice with this thread and hope some of you will benefit from this post.