Blessed Library: Something that is not part of the core offering but is the recommended way of doing certain things by the core maintainers. The main reason it is not in core is that it is probably not needed by all users of core.
I would say one of the the strongest blessings is inclusion in the create-react-app boilerplate. Of course that's ReactDOM not RN. Not sure if RN has an equivalent, or if even necessary since it's a complete framework.
:)