Altium2kicad can help you migrate an Altium project to KiCad, it supports most features of .PcbDoc and .SchDoc, so it can convert both the PCB and schematic. It consists of a few perl scripts that are executed on the altium design files.
KiCad StepUp is a FreeCAD Workbench aimed at helping both KiCad and FreeCAD users in collaborating with electrical (ECAD) and mechanical (MCAD) design.
Load kicad board and parts in FreeCAD and export it to STEP (or IGES) models
kicad_mod footprint in FreeCAD to easy and precisely align the mechanical model to kicad footprint
Pull a pcb edge from a
kicad_pcb board, edit it in FreeCAD Sketcher and push it back to kicad
Push & pull 3D models positions between FreeCAD and KiCAD
KiCost is intended to be run as a script for generating part-cost spreadsheets for circuit boards developed with KiCad. It works by scraping part distributor websites to get part pricing. Additionally, KiCost supports other bill of material files from other EDAs which is useful for older projects and it can even handle hand-made CSV files. KiCost also comes with a graphical user interface in addition to command line.