"The Slack app is displayed on a mobile phone, Tuesday, Jan. 31, 2017, in New York. Slack Technologies is hoping to convert more big businesses to its online business messaging service by making it easier for workers in different departments to communicate with each other. The new option, called ""Enterprise Grid,"" represents another major step in Slack's attempt to get more workers and employers to lessen their dependence on conventional email and embrace its service instead. (AP Photo/Mark Lennihan)"