This app hits Ethplorer API to show ETH and tokens for your address.
If disconnected you can view the portfolio of any address by replacing address query param in the url, e.g.
https://eth-portfolio.vercel.app/?address=0xbdfa4f4492dd7b7cf211209c4791af8d52bf5c50
yarn web:devstarts the web app at http://localhost:3000