If you're doing games (or apps that don't require native UI), I strongly recommend HaXe/OpenFL (http://www.openfl.org/) for crossplatform+native. It's what I used for Lightbot (http://light-bot.com/) and a few other games. Best Game of the Year Winner (according to multiple sources) "Papers Please" was also built on it.
Again, its native UI support is lacking (ie Keyboard, Input Textfield interactions) but otherwise the framework is opensource, solid, and compiles to native from HaXe (based on a similar structure as Actionscript 3) including to Windows, Mac, iOS, Android, Flash, HTML5+WebGL and more.
Again, its native UI support is lacking (ie Keyboard, Input Textfield interactions) but otherwise the framework is opensource, solid, and compiles to native from HaXe (based on a similar structure as Actionscript 3) including to Windows, Mac, iOS, Android, Flash, HTML5+WebGL and more.
They also have a great list of apps developed with their platform at http://www.openfl.org/showcase/
Edit: Links