Since now Android and iOS are both supported. Maybe the next step is to consider on Windows Phone? However, there seems not to have a clear answer on the official site.
Great News :)
Facebook’s React Native gets backing from Microsoft and Samsung. In F8 2016 they have announced the support for Windows 10 Universal App Development.
With this coming in, React Native will be supported on all the major platforms (Android, iOS, Windows 10)
Microsoft has already integrated Windows 10 support on existing React Native React Native Windows - Github
They have also build an App and planning to showcase the same on coming May 6. React Native Windows 10 App