FileProInfo - It's All About Files, Software, Online Tools - 100% Free
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.
File-Extensions.org - Large computer file extension library with detailed explanation of each file type with links to download free or associated software programs.
Airtable - Airtable works like a spreadsheet but gives you the power of a database to organize anything. Sign up for free.
GroupDocs - GroupDocs is a web-based service for online document sharing, collaboration and management.
Creativity 365 - Cross-device content creation suite