[pjmlp]

For me C++ is all I need for portable native code, no need to add extra layers that kind of work, that only increase code entropy and debugging efforts.

Directly available in iOS, Android, WP, Tizen, Ubuntu SDKs.

The only major problem is the way Google disregards their NDK stack, while Microsoft and NVidia engineers are able to do what Google PhDs are not.

[skrebbel]

How do you build the ui? Just push pixels? Or vertices? Some library maybe?

[pjmlp]

Since I care mostly about game related stuff, Cocos2D-x, SDL, openFrameworks.

When doing more app like coding, following MVVM patterns with the view written in the platform language.

On iOS you can use Objective-C++, on WP and UWP C++/CX.

Android is the worst because Google keeps the NDK at an arm's length, but projects like Djinni and SafeJNI help.

If you don't bother to provide a native experience, but still enjoy the portability of C++'s code, there is always Qt and QML.