There is an IOS App that allows you to count your tracks up relatively quickly. There is probably am android equivalent.I already have that for And, and I'm sure there are free apps for iOS. However, I find it's not that much different than using a regular calculator. The PITN part comes from going around the board, and making sure you hit everything without counting a route once.
I guess when I am playing the physical board game, I like counting up the scores at the end by hand. It's one of those tactile things that are great about physical board games as opposed to their electronic equivalents.
That being said, I do understand that some people may not want that.
Just my 1/50 of a dollar.
I get into the habit of scoring as you go, as I find that saves more time in the long run vs. having to score at the end.
An "auto app" would also count LR.
It's definitely possible to do although I'm not going to attempt it since my coding would probably be awful. At any rate, the only game this does NOT work for is TTR: Africa, which could throw a wrench into things unless you marked the tracks somehow to show the double points. Huh... I'd think a programmer would want to write code to automate exactly these sorts of things
If I were a programmer, I'd do the quicker method, which is to just count up the tracks.