This is a tool to convert csv files to plist files. Instead of having to deal with Apple's xml format directly, you can use Excel, Numbers or any spreadsheet tool of your liking to set up the data and export it as a csv file to convert using this app. The result is an xml based property list file.
Credits go to Danilo Campos who wrote this tool and published the source code. I just made it compile on today's Macs.
Original source code: https://code.google.com/archive/p/danilobits/source/default/source