One of the more trouble-free public tools I've authored is a pricing hotsheet generator for the Angeles Millwork website. Each week a script runs to update the pricing information displayed in a chart.js graphic on the page, fills out HTML tables, completes an excel-templated PDF with new pricing data.
The end result is an almost entirely automated process that has saved a considerable amount of time over the last couple of years. Previously, our advertising coordinator had to manually update the website and excel files - a process that was both time-consuming and repetitive - an excellent challenge to be solved with automation.
Left: Chart.JS line graph showing pricing Right: PDF Hotsheet