Canny - Canny helps you collect and organize feature requests to better understand customer needs and prioritize your roadmap.
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.
Delighted - The fastest and easiest way to gather actionable feedback from your customers
Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community
Promoter.io - Promoter is designed to capture actionable and accurate customer feedback that reduces churn and drives growth
Zendesk - Zendesk is a beautiful, lightweight help-desk solution.