If you have a server available, have some time and don't mind fiddling with some config files, you could install a Matrix homeserver. Matrix is a relatively ne

If you have a server available, have some time and don't mind fiddling with some config files, you could install a Matrix homeserver. Matrix is a relatively new open source message protocol that offers various bridges to connect to other chat/messenger services: https://matrix.org/bridges/ https://matrix.org/bridges/