productboard - Beautiful and powerful product management.
UseResponse - Open-source, self-hosted customer feedback software, live chat and helpdesk system that you can install on your server. Organize documentation using knowledge base and get feedback from social networks with centralized system
StoriesOnBoard - StoriesOnBoard helps agile teams build better products faster. The built-in guide helps you collect and prioritize ideas, understand user requirements, gather customer feedback, and validate feature ideas with internal & external stakeholders.
UserVoice - UserVoice integrates easy-to-use feedback, helpdesk, and knowledge base management tools in one platform that empowers users to speak and companies to understand.
Roadmap Space - Customer feedback & product management software for SaaS teams.
Zendesk - Zendesk is a beautiful, lightweight help-desk solution.