Skype makes it easy to start work calls in Slack
 

If you think the one thing Slack is missing is the ability to start voice/video calls, you're in luck. Skype released a preview version of its Slack integration, allowing you begin calls inside the workplace chat room app. Once you add Skype's new fe...

http://www.engadget.com/2016/01/14/s...alls-in-slack/