If there was, many would be doing it...and many have tried in the past. They either failed before being able to release after realizing that it was legally a large risk, or they tried and eventually got pressured into being taken down (if they didn't have malicious intent to begin with).

Don't let that kill your innovative spirit. Pivot to trying to build a DEX. If you want inspiration, check out demex. I recently found out about them, they're a decentralized exchange with centralized-exchange like functionality, with a working beta product that is not just cross-chain but also bitcoin-compatible.