Prepare the environment

Create nodejs environment via conda

conda create -p env nodejs=8

# Install the react native command line interface
(env) $ npm install -g react-native-cli

#This will create a new project for the application
(env) $ react-native init <project/application name>

# Enter the project directory ($ cd <project>) and 
# use this command to launch the iOS simulator:
(env) $ react-native run-ios

Killing whatever is using port 8081 with lsof -n -i4TCP:8081