Most Producers start out with websites like Trello and Hack N Plan and then move onto bigger things such as JIRA, Asana, or other similar websites. Honestly, though it is truly dependent on what you are trying to achieve. Hack N Plan is great for small teams with small fast goals whereas JIRA is way more intricate and takes a lot of time to fully learn and understand, but in the long run for a large project managed by multiple Producers, this would be one of the better options.
