pipedrive.com
In short: Pipedrive Marketplace (pipedrive.com) accepts public crm integration. It is free to submit, takes a moderate amount of preparation, and scores 66/100 on our impact ranking (useful).
Build an your tool Pipedrive app using its API, test it in a sandbox, and request public distribution.
Requires a real API integration, secure OAuth, listing materials, and marketplace approval.
Priority is medium, which sets the band. It is free and moderate to complete, which adjusts it within that band. The score ranks your queue — it is not a measure of domain authority.