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.
Stonly Knowledge Base - Interactive knowledge bases and help-centers
Notion - All-in-one workspace. One tool for your whole team. Write, plan, and get organized.
Free Knowledge Base by Dashly - Optimize your customer support with Knowledge Base by Dashly
Slack - A messaging app for teams who see through the Earth!
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.