I studied International Financial Analysis at Newcastle University, and most of that came down to running proper statistical analysis on datasets, week in, week out. The problem was SPSS. It's a fine tool, but it only really works on a laptop, and lugging one around just to run a test felt daft when I already had an iPad that could do everything else.
So I started building something for myself: a way to do real statistics on an iPad, not a cut-down version of it. There wasn't anything else out there that did that properly.
That personal project became Statesis. First the engine that does the actual maths, then the app around it. I'm still the only person building it.