Hogline is a curling scorekeeper and shot tracker for Apple Watch.

Curling rewards practice like any other sport. You get better at draws, at hits, at one turn before the other. The difference is that the people playing are also the people keeping score, in gloves, on ice, with a broom in one hand. So the scoring happens on a scrap of paper, and a scrap of paper can tell you who won but not how you threw.

Hogline moves that to your wrist. Logging a stone takes three taps: draw or hit, in-turn or out-turn, and how it landed. Scoring an end takes two. Look down mid-game and you see the current end and the running score in yellow and red, the same as the board at the club.

When the game ends you get your shot percentage, split by shot type and by turn, plus every end with its result and accuracy. That part is why I built it. I knew my out-turn draws were bad. I had no way to prove it, and no way to tell whether they were getting better.