Free "Adobe AIR Desktop, Android and iOS Development Starter" Course Udemy

While Apple really wants you to code in Objective-C and Google wants you to develop in Java for Android, Microsoft wants you to develop in .net and blackberry in... you get the point how can one person build in so many languages and more over then that do you really need to start from scratch for each output application?The answer if you ask these companies respectfully would be yes as they would love to lock you into one language there language. So much so that when Adobe Air was initially released to support iPhone, Apple slipped the rug under Adobe's feet and made it illegal to deploy applications using Adobe Air on the early days of iPhone. The good news is even Apple realized they can't fight this and Adobe Air is now fully supported on Apple, Blackberry,Android, Televisions, Desktops (mac and pc) and more.
The basic idea is simple. You just need to know one powerful language AS3 and with it you can develop applications for all the supported mobile and desktop options.
The run-time provides a consistent cross-operating system platform and framework for deploying applications and therefore eliminates cross-browser testing by ensuring consistent functionality and interactions across desktops. Instead of developing for a specific operating system, you target the run-time.