Use it for the following messenger and chat like a boss:
WhatsApp, Facebook Messenger, Telegram, Skype and Slack

Features:
- Send Photos and Videos directly to & from your system.
- Get respective Notifications alerts and reply from the same.
- Go Full-screen! Chat with your friends distraction free on the full screen mode.
- Check if there are any unread messages, right in the menu bar.
- Light weight which consumes minimum system memory about 70% low.
- 80% Low battery consumption.
- One app for all messengers.

Upcoming update:
- More chat services.
- Using multiple chat accounts for same service.
- Password Protection.
- And much more.

Privacy & Security
- One Chat does not read anything you type, send or receive! It does not even store any of your login credentials anywhere. Each messenger lives in its own tab, which can not be accessed by other messengers.
- Overall, using One Chat does provide a couple of advantages when it comes to security.

Disclaimer:
One Chat is a third party App. The developer of this software is not affiliated with Whatsapp Inc. Facebook inc. Telegram Inc. Slack Inc. Skype Inc. in any way.

Compatibility: OS X 10.10 or later

Home Page - https://itunes.apple.com/us/app/one-chat-all-in-one-messenger/id1139742811?mt=12