This is the very rough and very quickly done code of the react native example from my WordCamp Dublin talk
If you want to set this up yourself. I've used expo to create and run the react-native app. You will need to download that first
To get started run
yarn install
or
npm install
Then open up the project in expo. For the firebase details, you'll need to create your own firebase account and then create a web project, fill those details into "Posts.js"
Finally you need a WordPress site to query, the query url is at the top of the file "Posts.js" and "Home.js" just change that to what your own wordpress url
There is also a wordpress folder in the project and this contains the functions.php of the twentyseventeen theme with the REST Api modifications
You will need to modifiy the firebase url to work with your project url. WordPress sends a HTTP PUT request on every update The url is at the end of the functions.php