I have an extremely useful (for a very specific need) vba module collection for excel spreadsheets - I have often considered rewriting in an app, but the graphing outputs always kill my interest. I use it whenever I’m working after 20 + yrs , there are now a few proprietary packages that do the same, but are very easily misused, so even I use them for clients I still work from my own rather archaic vba assisted spreadsheet. I used vba because the calculations I was doing simply exceeded the abilities of spreadsheets - too many lines, it’s was an unusual discovery when I realised that my spreadsheet wasn’t fully evaluating the data set - handling just numbers and a vba module has never presented a problem.