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.
Unity - The multiplatform game creation tools for everyone.
Notion - All-in-one workspace. One tool for your whole team. Write, plan, and get organized.
Godot Engine - Feature-packed 2D and 3D open source game engine.
Slack - A messaging app for teams who see through the Earth!
Blender - Blender is the open source, cross platform suite of tools for 3D creation.