FIRST - Post a date, pick a winner & meet up.
productboard - Beautiful and powerful product management.
Marketing Teams and Slack - A handbook for marketing teams to make the most out of Slack
Aha - Aha! is the new way to create visual product roadmaps. Web-based product management tools and roadmapping software for agile product managers.
Startup Marketing Playbook - The how-to guide for new B2B marketing leaders
ProdPad - ProdPad helps your team gather ideas, surface the best ones and turn them into product specs, and then put it all on a product roadmap.