Build a DApp using window.ethereum injection. For even more fun, deploy a contract with HardHat or Truffle onto the testnet and use Coinbase Wallet or Metamsk to interact with it on your DApp 🙂

Ideas

I build a micro-financing DAO as part of a hackathon in 2021 — curvegrid.github.io/bitfinca

I built a react app to test out all WalletLink functions — sign transaction, send eth, etc. this helped me get well versed with web3.js