Slack - A messaging app for teams who see through the Earth!
Quip - Quip is the modern productivity suite that simplifies your life and helps your team get work done faster.
Cirrus Insight - Respond to Customers Faster and Update Salesforce from Your Inbox with Cirrus Insight. Start your free 14-Day trial today! No Credit Card Required.
Google Docs - Create a new document and edit with others at the same time -- from your computer, phone or tablet. Get stuff done with or without an internet connection. Use Docs to edit Word files. Free from Google.
Microsoft Teams - Microsoft Teams provides the enterprise-level security, compliance and management features you expect from Office 365, including broad support for compliance standards, and eDiscovery and legal hold for channels, chats, and files.
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.