The tool described is Planning Poker. It is a consensus-based technique used by agile development teams to estimate the relative effort or size of development goals in software development. Each team member uses cards with numerical weights, such as the Fibonacci sequence, to indicate their estimation of the complexity of a user story. The team members flip over their cards simultaneously, and any outliers, high or low values, are given an opportunity to explain their reasoning to the team. The process is repeated until a consensus is reached on the complexity of the user story. Planning Poker is often used in Scrum and other agile methodologies to plan and prioritize the work that needs to be done in an upcoming iteration.