If you're looking for a tool to help your team collaborate on brainstorming and design thinking projects, Slatebox is a great option. It's a visual collaboration platform that uses AI to generate editable diagrams based on natural language prompts, so you can get a fast start to real-time collaboration. Slatebox features include auto-generated diagrams, real-time note taking, customizable templates, and a large library of shapes, making it great for mind-mapping, brainstorming and design sessions.
Another good option is Seenapse. This tool is great for generating hundreds of creative ideas rapidly. It's good for divergent thinking, coming up with novel and surprising ideas, and can be integrated with Google Docs for easy collaboration. Seenapse is geared for creative directors and teams that need new and creative ideas, so it's a good choice for brainstorming.
If you're looking for a more full-featured project management tool, check out ClickUp. It's an all-purpose project management tool, but it's got collaboration features built in, like centralized communication, customizable views and integration with other apps. ClickUp is good for teams in marketing, product development and design, and can help you get work done more efficiently.