How and where do I get the application to use the Atomic Swap?
You can test the Atomic Swap technology using protocol’s source code at https://github.com/minexcoin/atomicswap
Or using MNX Atomic Swap GUI https://medium.com/minecoin-blog/mnx-atomic-swap-gui-let-the-tests-begin-42b791ddbb41
NOTE: Keep in mind, atomic swap currently runs on testnet of each cryptocurrency you exchange.
Testnet is a network where you only use test coins. Test coins are aimed at testing some features or functions. Test coins do not have market value.
Mainnet - is the main network, where the coins with market value are operating.