Cross-platform mobile development. What tool do you use?

Question

To those who don't develop native Android/iOS apps, there are many cross-platform tools available, such as:
Sencha, PhoneGap, Appcelerator Titanium, Cocos2d, Unity 3D, Corona, QT, Xamarin, Alpha Anywhere, 5App, etc.
What tool do you use and why?

Answer 1

https://kivy.org/ naturally appeals to every Python programmer. Also, it's conveniently MIT licensed, which makes it usable for open source and biz projects alike.

Answer 2

i think the best by far is .net
https://www.microsoft.com/net