Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
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.
Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community
Notion - All-in-one workspace. One tool for your whole team. Write, plan, and get organized.
Zoho Desk - Industry's first context-aware Helpdesk Software
Slack - A messaging app for teams who see through the Earth!