Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.

Airtable - Airtable works like a spreadsheet but gives you the power of a database to organize anything. Sign up for free.

Eventbrite - Discover Great Events or Create Your Own & Sell Tickets

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.

Bigtent - BigTent is a web-based organization and communication portal for groups.

RingCentral Video - Live life unlimited. Free video meetings and team messaging in one app that works the way you do.