MySQL - The world's most popular open source database
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.
PostgreSQL - PostgreSQL is a powerful, open source object-relational database system.
Notion - All-in-one workspace. One tool for your whole team. Write, plan, and get organized.
SQLite - SQLite Home Page
Slack - A messaging app for teams who see through the Earth!