productboard - Beautiful and powerful product management.
Iterate - Get the feedback you need to build better products
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.
Aha! Business Model Builder - Create the perfect strategy for your product roadmap
ProductPlan - Cloud-based product roadmap software solution
ProductFlare - Kickass roadmaps & product management software