Other applications that I developed from scratch, many years ago:
Operating Orders A database application to create and store operating orders for high-voltage switching, it also made it quicker to write a new operating order by offering shortcuts to create multiple steps, e.g., to open a switch, prove de-energised, and apply earths (I was a substation operator at the time). The link is to the user guide. At one point in time this was used at substations across the North Island of NZ. It was based on an early GUI database called Superbase, which unfortunately disappeared.
Line Design A combination of spreadsheet macros and LISP code to transfer survey data into AutoCAD and produce a drawing, to replace the extremely manual process of calculating rises and falls and then entering these in as drawing points (I was working in the Drawing Office at the time). The link is to the document that was presented at a distribution company coference. Based on an early programmable spreadsheet called Framework, and AutoLISP which is used to automate AutoCAD actions.