What’s better for a blog mobile app

I assume your using this on the backend? either way it depends on what your comfortable with each has there pro's and con's although I tend to work with NodeJS since I'm already familiar with JavaScript.

both are run with nodejs -_-

I would not go for nodejs..I do not like javascript for backend, maybe because I am the java guy :D

what do you mean by react native or nodejs, react native is a javascript framework

awesome

"blog mobile app" sounds like you could easily take some cms like wordpress, enable the "blog" feature and it will render on all devices equally