Telegram
Free
Telegram is a free cloud-based instant messaging platform.
IM+
Freemium
IM+ supports simultaneously major IM services, including Google Talk, Twitter DMs, Yahoo!, AIM/iChat, ICQ, Jabber (and Slack through Jabber), etc.
Trillian
Freemium
Trillian is a proprietary multiprotocol instant messaging application.
Matrix.org
Open Source
Matrix is an open protocol for real-time communication. It is designed to allow users with accounts at one communications service provider to communicate with…
