At an event in San Francisco Monday evening, Slack CEO Stewart Butterfield said that his company was going to stay focused on its namesake app, a tool for team collaboration, rather than spinning off a bunch of new apps.Butterfield was at Galvanize, a coworking and events space in San Francisco's SoMa district, to chat on stage—well, on stools—with John Battelle, the longtime journalist and entrepreneur whose latest venture, NewCo, was kicking off a multiday tour of tech companies in San Francisco and Oakland.Do We Want A Slack Office?During a brief question-and-answer session after their chat, I asked Butterfield if Slack—whose core app is now used by more than 1.25 million people per day—was going to remain a single-app company or turn into a suite of apps for team productivity.Butterfield said a lot of people expected Slack to expand from messaging to group calendars and task management, "perhaps because they've been trained to expect that by Outlook," Microsoft's email software that combines those features.See also: Inside Slack: How A Billion-Dollar Email Killer Gets Work DoneInstead, Butterfield explained that Slack's strategy would be to make other apps better.