This is a GUI utility which renumber KiCadPCB reference designators in a logical fashion (i.e. top to bottom, left to right) and back-annotates the schematic, functionality which is missing from KiCad. Usually when you assemble or debug a board you need to locate the components on the PCB and renumbering makes this much easier. I have included more details in the file RenumKiCadPCB Readme file in the repository, which also include complete build instructions as well as a Windows32 install package.