Are there any diagramming and ideation platforms that focus on remote brainstorming sessions?

Yes — several platforms are built specifically for remote brainstorming and collaborative ideation, not just general diagramming. A few strong options:

Remote brainstorming / ideation focused

• Miro — Very popular for remote workshops, whiteboarding, sticky-note brainstorming, mind maps, and structured facilitation.
• Mural — Similar to Miro, with a strong emphasis on collaborative workshops, sticky notes, templates, and facilitation tools.
• FigJam — Figma’s whiteboard tool; great for lightweight ideation, team exercises, and visual collaboration.
• Klaxoon — Designed for interactive workshops and brainstorming sessions, often used in enterprise settings.
• Stormboard — Built around sticky-note brainstorming, prioritization, and decision-making workflows.
• Conceptboard — Good for collaborative visual planning, brainstorming, and annotation.

More diagramming-oriented, but usable for ideation

• Lucidchart / Lucidspark — Lucidspark is the more brainstorming-oriented whiteboard; Lucidchart is more diagramming-focused.
• Whimsical — Clean, simple collaborative whiteboarding and mind mapping; lighter-weight than Miro/Mural.

If you want a more “meeting” style experience

• Microsoft Whiteboard — Useful if your team is already in the Microsoft ecosystem.
• Zoom Whiteboard — Convenient for brainstorming directly in Zoom sessions.
• Google Jamboard was the classic option, but it has been discontinued.

Best picks by use case

• Best overall for remote workshops: Miro or Mural
• Best for simple, fast ideation: FigJam or Whimsical
• Best for enterprise workshop facilitation: Klaxoon or Stormboard
• Best if you already use Figma: FigJam
• Best if you want diagramming + brainstorming: Lucidspark/Lucidchart

If you want, I can also give you:

1. a comparison table,
2. the best options for a specific team size or budget, or
3. tools optimized for async vs live brainstorming.