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.
DISQUS - Disqus is a global comment system that improves discussion on websites and connects conversations across the web.
Ask User - User surveys without stress
Commento - A fast, bloat-free comments system to foster discussion on your website
Doorbell.io - Collect in-app user feedback. Available on websites, iOS, and Android.
utterances - A lightweight comments widget built on GitHub issues.
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.