One issue I've seen with the digital scoring is that the order of players change....so it is easy to mark a score for a wrong person if you aren't paying attention. Player 1 is always first on the tee, get used to that when entering scores, then Player 1 has a bad hole and drops a spot or two....now you could think they are still in #1 spot and mark is so. But that also means you aren't paying attention to the app as it shows the names. Paper/pencil, the order on the scorecard is always the same for the round. I've seen this happen in a league, the digital player called off the names to get scores and the paper/pencil scorer put them down in the order on the paper:, for example, four players start in this order A, B, C, D. At the start the digital and paper card's order match. But then, a few holes in.....
Digital calls for scores in order: A, C, D, B
Paper writes scores in order: A, B, C, D
(Player A's score on both is okay, but then the digital scorer asks for C's score and the paper scorer puts it down as B's score).