You probably want to test your app before uploading to the app stores. Here I will explain how to test the app on your local machine (laptop or desktop)
Here, I'm going to take you through the steps that will let you install and test the application on your local machine (laptop or desktop) using iOS Simulator and/or Android Emulator.
Skip (Step 1 and Step 2) if you already have node and npm or yarn installed.
Step 1: Install Homebrew (MacOS only)
Homebrew is "The missing package manager for macOS". Open terminal and type the following command.
$ cd yourAppFolder // USE THE ACTUAL NAME OF YOUR APP FOLDER
$ yarn install
$ cd ios
$ pod install
$ cd ..
// AFTER RUNNING THIS COMMAND, IT MAY TAKE SOME TIME TO BUILD THE
// APP BEFORE IT WILL RUN (TRY TO PRESS RELOAD SEVERAL TIMES IN CASE
// BUILDING IS COMPLETED BUT AN ERROR APPEARS)
$ yarn run ios
or
$ yarn run android