Caddie & trainer, GPS distances, scorecards, and stats on your wrist. Course map editing & distribution for clubs.
A brand-new golfing app has just launched!
In a unique venture, we’re introducing a fresh sports app called Golf Quartz. My own golf journey began about six years ago when my father brought me along for a discovery session. The sport is challenging—it still challenges me—but I was instantly hooked by its rich blend of outdoor activity, the pursuit of perfection, ongoing humble learning, and the chance for social and generational exchange. It’s become clear to me that golf is more than just technique; it’s increasingly a lifestyle. But let’s pivot back to our app.
What distinguishes our app this time are several key features:
- It is built from the ground up for the Apple Watch, leveraging sensors, AI, and more. It’s not merely an adaptation from an iPhone app.
- It's actually not one app but three apps: Apple Watch, iPhone, and Mac + the cloud.
- Course mapping is brought back to those who know the course best, clubs and players. And trying to do in a decentralized way to benefit everyone.
- Open data is central: data formats are open for course maps and game data with free access and import/export.
Golf Quartz is available on the App Store, and more information can be found about it on our website.
The concept
It all started from my difficulty as a beginner to keep my own scores & those of other players. It can be a real challenge when you're under the game pressure, and not too familiar with counting, even after a couple years. From that starting point (score keeping), we evolved the concept to provide valuable information during the game like flag or hazard distance and location of the next tee for unknown courses, together with AI to let the watch know when (& from where) you're swinging. Finally, it became obvious we could do more by analyzing the swing motion when practicing & provide valuable feedback like amplitude, maximum speed, etc.
Many of my friends have an Apple Watch, but they typically switch to a specialized watch when playing golf. These can be good at golf, but I felt like we could do something to make a better use of their Apple devices which are actually packed with the latest GPS, processing power / AI, a refined user experience and a large choice of apps for everything, and pretty unique high-speed sensor technologies.
From a beginner-oriented initial idea (score keeping), we evolved it during development into something that could suit golfers of any level (customized course information, swing analysis). That came down to our skills at app making: offer a progressive complexity and a diversity of tasks for the variety of needs, yet never interfere with the game, keeping the distractions out and the mind free & focused on the game itself, which is what really matters for golfers.
A "watch-first" experience
Apple Watch is packed with sensors and has gained increased processing power years after years. watchOS 10, required by Golf Quartz, is now bringing the kind of capabilities that enable the complete experience.
Very early in the concept of this app, we quickly identified that the watch was the best place to keep the scores on the course because it is always with you. Indeed, if you happen to have your iPhone on the trolley and move it to the next tee before finishing with the green, it's not with you anymore, and you can't count the last strokes as they occur. The always-with-you thing is an absolute asset, but there's more to it.
In the early years of the Apple Watch, processing power and sensors were quite limited, as were the development capabilities to offer full-fledged user experiences. But as the time advanced, real APIs and highly accurate sensors appeared and created new possibilities. Health related tracking, AI swing detection & analysis, precise GPS-based positioning & distance determination have all become a reality.
Companion apps on iPhone and the Mac are offered respectively for reviewing past games/practices and for mapping courses. We tried to use the form factor that makes the most sense for each task, that is, reviewing past games make more sense on the iPhone than on the watch, and tagging courses with a precise mouse and a large display makes more sense than doing it on a phone.
A caddie on the course
As previously mentioned, score keeping was the first thing we were trying to solve. It had to work with multiple players, as this is how competitions make you do it: you have to count your own strokes and the ones of another player. We pushed it further to allow up to four players, although this is more for caddies as it requires many interactions while playing, but it's there.
Distances to greens, tee targets and hazards were all implemented on top of GPS positioning. We found it to be pretty accurate, especially on Apple Watch model feature double-frequency GPS. We complemented it with magnetometer data to provide direction in addition to distance, in the form of a compass-like arrow. Next tee, green, and tee target use that feature, and we find it particularly useful when you discover a new course: "Where should I aim? Where's the next tee? Etc.". It's also a pretty unique feature, as this requires not only the sensor but a live display for it to work that not many golf watches offer.
A pro at the range
Not telling that the app will replace a pro, of course not. But it can definitely complement it. A golf swing is a complex whole body motion, and it needs to be analyzed thoroughly. Yet, when working on a few detail points like the duration of transition between the backswing and the downswing, or the maximum rotational speed, or backswing angular amplitude, measurements can be made and provide valuable feedback. And this is a pretty unique feature that Golf Quartz provides. Unlike radar sensors that provide club head and ball related speeds and trajectories, Golf Quartz does not focus on the results but more on the motion itself that produces such results. Bound to the wrist, it can precisely determine rotational pace and related metrics to estimate motion information that can help training specific aspects. Based on high-speed sensors of the latest Apple Watch models, this is a pretty unique feature that most other watch brands can't replicate.
Golf Quartz will mirror these computed metrics both to the iPhone display when training (attached to the bag for instance) or use text-to-speech to announce the latest swing focused value. If your transition is too quick, select the transition value (milliseconds), and let the watch speak it to your AirPods after each swing as you try to increase its value by slowing down between backswing and downswing. Or validate that 1 month at the gym with specific exercises will indeed augment your maximal rotation speed in the downswing. Good practice is all about gathering useful feedback, and Golf Quartz will happily provide it for you.
Artificial intelligence
The watch app does make use of artificial intelligence. While playing or practicing, it continuously detects swings and putts to refine data of other subsystems. We initially thought that it wouldn't be possible to have an LSTM processing sensor data continuously for 5 hours+, but found out it actually was the case (good job CoreML team). Selection of sensors, recording and preparation of training data and handling of various watch configurations (left/right handed, watch orientation, etc.) were performed to train the model.
We expect to do more with AI. For instance, fully automatic counting based on AI is not yet possible (was too noisy), but we still use AI to filter out false scoring alerts in single-player score keeping (because in multiplayer situations, the watch doesn't know when others are swinging).
Collaborative course database
Even though multiplayer scorekeeping was the initial idea for the app, we quickly realized that providing distances on the course was too fundamental a feature for us to ignore. We explored existing databases, and determined that they were both expensive (cost that we'd have to pass to our users) and inaccurate in that they don't cope well with course changes, temporary like weather/season based, or definitive like mods or relabelling of holes. More fundamentally, it just makes sense to have a decentralized mapping task in the hands of those who really know the course. These were the starting thoughts about a mapping app.
This app was initially conceived as an app that players could use to map their own course, and share files together at the club. But sending files and managing versions could quickly become a friction. So we opted pretty late in the development cycle to go with a full-fledged cloud platform that not only players but also clubs could use to automatically distribute their maps to everyone. With all the advantages described on the site: same-day delivery of changes, get back control of the data, have happy members throughout seasons and course changes who will be able to use their watch at all time.
It was also an excuse for us to try new technologies like Swift on the server, which enabled us to quickly iterate by sharing code with the apps.
Developers' journey
We started out with the project under watchOS 9. It was doing pretty great, until watchOS 10 was announced last year at WWDC 2023, which was a major update for Apple Watch. We had to reconsider how to navigate within the app to provide an experience that is better aligned with the newest paradigms presented then. This was quite a challenge. Another difficulty that arose with the betas in the summer and fall, was that location access was mostly broken for watch/iOS companion apps, which in turn slowed us down massively as we couldn't test development builds for months, always trying to find workarounds. It finally returned to normal a couple months after the official OS launch, and we could finally iterate more effectively.
Similarly for the iPhone app and the mapping app on Mac, we decided to go with SwiftUI, which recently integrated a refined API for Apple Maps. Working with SwiftUI forces you to make radical design choices (as not everything can be achieved), but under those constraints, development can become quicker. Like for watchOS, we experienced a number of issues in the most recent OS APIs, but finally converged.
A note about open data & evolutions
It is important to me as a golfer (and even more generally as a user) to not be captive of some ecosystem, that is, if I stop paying all my data is gone. I actually think this is a hostile business model of the past, and strongly believe instead that offering a user experience around more open data is what makes sense in the end. That is why we opted right from the start for open formats (that others can use too) both for game data and for course mapping.
We also hope that bridges between systems, like having the watch directly send scores to an automated competition dashboard at the clubhouse, smart weather alerts, or a club-operated virtual marshal (for alerts, not electrical discharges) will become a reality at some point.
And above all, just keeping it simple and sound for a relaxing game. Thank you for reading.