Not necessarily my own use, but I built a few tools (that I volunteer free for use on a perpetual license) for my day job to make life a little easier in a few departments. Nothing impressive imho, they're mostly 'basic' calculators for various parts of the wiredraw process, from basic reduction-of-area to full-blown multi-pass die calculators (all fairly basic math and algorithms). In all honesty they're the kinds of semi-basic tools that the company should already have after >50 years of continuous operation, but stubborn blue-collar workplaces can be set in their old-fashioned ways, no matter how inefficient (honestly it's somewhat nice seeing others using and appreciating something I built).