Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
Lineup - build teams, not spreadsheets
Live Chat by Sumo.com - Instantly communicate with customers, prospects & visitors
Hyper Island Toolbox - Methods & Tools to improve team collaboration & creativity
Drift - A messaging app that helps you grow your business.
Timbo - Retrospective tool for remote teams, that covers all agile retro stages and is fully customizable