How do you keep score in mahjong without paper?

Question

Accepted Answer

Use a scorekeeper app on one phone. One player records each hand, the app names the winning hand, works out the total and who pays whom, and everyone else follows the same board live from their own phone — no pencil, no running tally, no arguing about the arithmetic. Paper works, and it fails in the same three ways every time: The arithmetic is the slow part of the night. Someone has to recognise the hand, add the lines, apply the minimum, and then work out three separate payments — while everyone waits. Only one person can see it. The pad sits next to the scorer, so the other three are trusting a column of numbers they never read. One wrong entry poisons everything after it. A running total carries its mistakes forward, and by the time anyone notices, the hand it came from is three hands back. A scorekeeper app fixes all three at once. The host taps the winning hand; the app names it, c

How do you keep score in mahjong without paper?

Keep score, beautifully