Xmind - Xmind is a brainstorming and mind mapping application.
productboard - Beautiful and powerful product management.
MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.
Aha - Aha! is the new way to create visual product roadmaps. Web-based product management tools and roadmapping software for agile product managers.
Viima - Viima is the simple, yet incredibly powerful Agile Innovation Platform that helps you go from ideas to innovations – at the speed and scale of a true innovator.
ProdPad - ProdPad helps your team gather ideas, surface the best ones and turn them into product specs, and then put it all on a product roadmap.