HeySpace - HeySpace is the only free task and simple project management software with communication and collaboration feature.
Slack Jira Integration - Easily keep issues moving right from Slack
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
Sortd for Slack - Get Trello-style project boards right in your Slack!
Jeski - Many projects, multiple boards, one Jeski
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.