List of free product-management stuff for developerππ½
If you're looking for all programming tools around product-management (not just free). Check this page List of product-management Programming Tools
SeaTable
SeaTable is the new flexible way for teams to work on tasks, projects or ideas.
Tag: product-management, collaboration, nocode, api, spreadsheet, database, task-management, productivity, remote
Unlimited number of tables 10,000 rows per account 2GB storage for file attachments Up to 25 team members 1 month versioning and snapshots Community support JavaScript and Python support

Miro
Scalable, secure, cross-device and enterprise-ready team collaboration whiteboard for distributed teams. Join 20M+ users from around the world.
Tag: product-management, remote
Unlimited team members 3 editable boards Anonymous board viewers Premade templates Core integrations Basic attention management

Asana
Work anytime, anywhere with Asana. Keep remote and distributed teams, and your entire organization, focused on their goals, projects, and tasks with Asana.
Tag: product-management
Unlimited tasks Unlimited projects Unlimited messages Unlimited activity log Unlimited file storage (100MB per file) Collaborate with up to 15 teammates

Cluctch
Clutch helps product teams go from prototype to production in real-time
Tag: product-management, collaboration, nocode
Free during Beta Build real products & components with real-time collaboration Unlimited private and public projects Community support