Two companies that seem to be using atomic swap are these: https://bleutrade.com/ and https://shapeshift.io/. I have used neither. I am only showing them as examples. You don't have to depend on the Lightning Network.

From https://www.reddit.com/r/BitcoinBeginners/comments/7aijlp/atomic_swaps_and_lightning_network/: "Are atomic swaps the transactions that occur in the lightning network? yes they have already been done as tests https://bitcoinmagazine.com/articles/atomic-swaps-how-the-lightning-network-extends-to-altcoins-1484157052/ - Can atomic swaps occur outside the lightning network? Sure. LN is just one payment channel implementation - Are the transactions that occur in the lightning network called atomic swaps? No. they are essentially HTLC bitcoin transactions. https://en.bitcoin.it/wiki/Hashed_Timelock_Contracts."

DON'T GET TRICKED BY THE LIGNTNING NETWORK. YOU DON'T NEED IT. From https://captainaltcoin.com/atomic-swap/: "You might think using an atomic swap requires a certain degree of trust, but that is not really so. Atomic swap is using a hashed time-locked contract, which is a part of the scripting language used for most major cryptocurrencies in existence right now. It has been added to Bitcoin Core on proposal of Peter Todd, a well known bitcoin developer."