CoinJoin
CoinJoin is an anonymization service that protects the privacy of Bitcoin users when they conduct transactions with each other, obscuring the sources and destinations of BTC used in transactions. It is available as open-source software and constantly developed by the bitcoin community.
CoinJoin is a way to obscure Bitcoin transactions in order to preserve more anonymity, as Bitcoin is a public blockchain with spending and transactions available to view by the public. Currently, BitJoin supports Bitcoin and Bitcoin Cash. It involves mixing addresses with a smart contract layer.