I am currently in a Shadowrun campaign where the freeware program "Chummer" is used extensively. Rather than keeping track of stats, expenses, equipment and the other minor details the program handily keeps track of them and I can get all the necessary stats out without writing down everything or going through a dozen books.
I am also in a campaign where we use google docs and Excel to keep track of food and supplies of the clan. ...We are keeping track of how much food each individual eats and item lists. When it was just 10 or so characters, half of whom were PCs this was simple and done in a notebook. Now that there are over 100 NPCs in the clan we have already progressed to Excel at some point (because losing your sanity over calculating food usage is just silly when few lines in Excel help get the job done.) and have plans to mainly replace these homebrew rules with Harn manor rules to make things easier. (It really was a snowball effect where things kept getting more complicated but it was so gradual that simply jumping to a different ruleset was not an obvious solution until we were late in the game. And we still plan to use the original RPG rules for most of the stuff but simplify the household affairs and have those be a separate game.)