I used Mark Broadie’s GolfMetrics app for part of the year last year.
During the round I mark tee box, then jot down 2nd shot distance and lie, 3rd shot distance and lie and so on. So a hole might looks like
Tee shot - 375 yards tee ground
2nd shot - 100 yards from rough
3rd shot - 30 ft putt
4th shot - 2 foot putt
The app will then calculate strokes gained for each shot and and the hole total. Then once you input the full round of data it gives strokes gained for Driving, Approach by distance ranges, short game, and putting by distances.
Takes about 5 minutes to input all the information into the app post round.
A few screenshots below for reference. I recall it being reasonably priced so I’ll use it again the whole of 2021.