This new platform called Electrode Native from Walmartlab is pretty powerful.

You don't have to throw away your existing native codes, you don't have to start from scratch your existing project to transform to react-native.
Developers can concentrate on functionality and building of their apps--without the hassles of reuse or integration issues

And it's open source too. You can check their GitHub library here.

It has only full support only on Mac OS at the time of writing this test.
It can be run in Linux too but more testing is required to verify.

Totally build on top of react-native.