A pivot report of billed and unbilled timesheet value for time-and-material projects, alongside the cost of the time logged.
For each project and period it shows the hours logged, their cost, and the billable value of that time, split into what is still to invoice and what has already been invoiced, so you can see how much delivered work is still waiting to be billed and whether it is profitable.
It is inspired by the Project Costs and Revenues report that was available under Project → Reporting in Odoo 14.0 and earlier, and removed in later versions.