On MacOS you can use brew, on Ubuntu you can use apt-get
Use nvm - node version manager (MacOS, Ubuntu) nvm install 8.4.0
Or install from offial webpage
https://facebook.github.io/watchman/docs/install.html
https://devcenter.heroku.com/articles/heroku-cli
> npm install -g yarn
or any other decent editor
https://code.visualstudio.com/download
node -v
# v8.4.0
watchman --version
# 4.7.0
yarn --version
# yarn version v0.27.5
git --version
# git version 2.14.1
code --version
# 1.15.1