Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.

Doorbell.io - Collect in-app user feedback. Available on websites, iOS, and Android.

Zendesk - Zendesk is a beautiful, lightweight help-desk solution.

Sleekplan - Embedded customer feedback management made for SaaS - The most sleek solution to collect and manage user feedback, keep a changelog and know your customers' needs.

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

User Insights - Get real user feedback on, well, anything.