Today's free open source software goodie is Franz. It ropes all of your messenger software into one handy package that lives on your desktop.
I downloaded it a couple days ago and once I got it set up (easy!), I started wondering how I lived without it. Currently I'm rocking Telegram, Twitter and Facebook Messenger on Franz, but I'm a moderate user of messenger services. The nice thing about having Franz on my desktop is that I can use more than one account for the same service. I have more than one Telegram account and, of course, I have both business and personal Google accounts to keep up with.
Franz supports a wide range of services including Slack, WhatsApp, WeChat, HipChat, Outlook, Github, Facebook Messenger, Telegram, Google Hangouts, Discord, Twitch, Skype just to name a few.
I've only touched the surface of this app's usability. It's open source, so there are plugins available. The services available for the platform will definitely grow as the number of users increases. Give the app a try!