Not really privacy/security oriented, but useful to those using different chat providers. Franz is a free messaging app / former Emperor of Austria and combines chat & messaging services into one application. He currently supports Slack, WhatsApp, WeChat, HipChat, Facebook Messenger, Telegram, Google Hangouts, GroupMe, Skype and many more. You can download Franz for Mac, Windows & Linux. http://www.meetfranz.com/#download_all
