Nifty - Manage projects, work, and communications in one place.
Userfeed - Product feedback made for Intercom
Intercom on Product Management - The ultimate resource for aspiring product managers
ClearFlask - Open-source Product Feedback Tool with a Public Roadmap and Announcements.
productboard - Beautiful and powerful product management.
Fider - Fider is an open source, cross platform and free to use customer feedback platform for companies...