Cross-chain BTC/DAI options trading protocol.
We built a proof of concept (incomplete) which included smart contracts for Put and Call options, support for pBTC as collateral and DAI for payment of option premia, and an on and off ramp for going between pBTC and tBTC.
Solidity for smart contracts, web3.py + flask for the incomplete DApp. pBTC<>tBTC app built using React and ptokenjslib.