Years ago, I wrote a .exe to change screen resolution, and then revert when closed. I used it when my old laptop had a composite out, and I would watch moves that I downloaded on a TV.
A few years ago I wrote a grid-scale battery simulator, scraped some publicly-available cost of electricity data, and calculated how long it would take for grid-scale batteries to break even when buying and selling power to-from the grid. Short answer: About 18 months. Long answer: Permitting a power plant takes a few years, and the permitting process only recognizes buyers or sellers. The permitting process doesn't recognize "storage" yet.
More recently, I wrote a quick-and-dirty utility to restart explorer.exe, because it has some really silly multi-monitor bugs that require restarting the process every once in awhile.
