It's flexible and does most things well. Support is amazing, they even added a feature for me!
Got a really high response rate. I used this in tandem with Promolayer on my EC site for CRO. I did a 'whats missing from this product description' type survey + post purchase + product follow-up email and frankly, it's been amazing. I spent about 2 years trying to figure out my direction via analytics and heatmapping when I should have just been talking to my users the whole time.
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
Ask User - User surveys without stress
Doorbell.io - Collect in-app user feedback. Available on websites, iOS, and Android.
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.
buddybuild - Buddybuild ties together continuous integration, continuous delivery and an iterative feedback solution into a single, seamless system. With buddybuild, you can focus on what matters most: creating awesome apps.
Zendesk - Zendesk is a beautiful, lightweight help-desk solution.