Franz is a multi-messenger client thingy.
Rambox also, too, similarly.
All-in-one messenger app works great. It's one app for Dischord, freaking WhatsApp, Hangouts, Facebook Messenger, Tweet Deck, pretty much whatever you got. Built on Chrome so it's cross-platform.
What is weird though is that the only way to actually launch it is to go to the store and hit the launch app button.
That is, until you dig deep down in the comments and find that there is a separate app just to launch allinone from the Chrome toolbar.