I am developing an application for Android. In order to complete this task I use an SDK and Adobe Flash Builder. Also there is a page that has valuable information regarding mobile application development. There are code snippets that handle the physical buttons and the rotation features of the mobile devices. I have just started developing but this page (if you became interested: newbielink:http://www.voip-sip-sdk.com/p_456-voip-android-integration-voip.html [nonactive]) provided me with useful information. I think others who are not familiar with this technology will find this page to be a good starting point.