Frill - A better way to collect customer feedback
Software Product Management Stack - Resources & tools to help you manage your software product
Canny - Canny helps you collect and organize feature requests to better understand customer needs and prioritize your roadmap.
The Product Management guide - A book on how to create and ship products that people love
Feedlify - Engage your customers build better products
Product Management Exercises - A repository of product manager job interview exercises