Twitch chat client for those who prefer a desktop application.
Franz allows you to group all of your messaging and chat services within one easy-to-configure application.

Exchange text messages and make audio and video calls.
Local network communication software between devices connected to the same network, without the need for an internet connection.
Modified version of WhatsApp with customization options and additional features.

Plugin for Microsoft Outlook that allows you to follow Twitter within the email client.