First, install the necessary tools in terminal:
brew install node
brew install yarn
yarn global add expo-cli
Next, retrieve the project source code and dependencies:
git clone https://github.com/kaaniboy/covidsafe.git
cd covidsafe/
cd app/ && yarn install
cd server/ && yarn install
Run the following in terminal:
cd app/
yarn start
From there, you can select to launch the app in a browser, iOS simulator, etc.