My swap machine coins.room-house.com swaps ETH clones like ETC, EXP, CLO, UBQ, etc ->RHC which is a Substrate clone. Can be any Substrate coin, like DOT, because NodeJS api is the same. Technically this is working to list any ETH->Substrate pair. Backward chain: Substrate->ETH is also working. Pretty sure with BlackCoin api can be tested to swap RHC to bitcoin clones. Then swap machine can swap between them all three: BTC,ETH and Substrate clones. With not much to do, it can be an Exchange.