UserTesting.com - Usability testing has never been easier. Get videos of real people speaking their thoughts as they use websites, mobile apps, prototypes and more!
The Product Folks - A volunteer-led community of product managers and makers
Instabug - The top apps in the world rely on Instabug for beta testing, user engagement and crash reporting.
Software Product Management Stack - Resources & tools to help you manage your software product
Userbrain - Easy, fast, and affordable user testing for websites and prototypes.
Product School - The global leader in product management training