Building Run Ri Run: Crafting a Custom Workout App for the Apple Watch
Sometimes the best ideas come from those closest to you. For me, inspiration struck when my wife began preparing for the Seven Hills Run in Nijmegen. As she trained, I noticed how cumbersome it was to create custom running workouts using the native Workout app on her Apple Watch. She needed something intuitive, flexible, and powerful to help her train effectively. That’s how Run Ri Run was born.
Leveraging Apple’s new WorkoutKit SDK, I dove into development. Seven weeks later, the app was live on the App Store—just in time for the big race.
Here’s how I turned this idea into reality.
The Problem: Simplifying Custom Workouts
The default Workout app on the Apple Watch is great for tracking basic activities, but when it comes to creating interval workouts or more tailored plans, it falls short. My wife needed to:
1. Easily customize workouts: Define warm-ups, running intervals, recovery periods, and cool-downs.
2. Work seamlessly across devices: Plan on her iPhone and execute on her Apple Watch.
3. Keep the focus on running: No complicated menus or settings while mid-run.
The challenge was clear: design an app that made creating and executing custom workouts not just easier but enjoyable.
The Solution: Run Ri Run
The idea was simple: allow users to create workouts on their iPhone and execute them on their Apple Watch. The app had to balance simplicity with functionality. Thanks to Apple’s WorkoutKit SDK, I could leverage native tools to integrate deeply with the Apple Watch’s health and fitness ecosystem.
The Development Journey
Week 1: Laying the Foundation
Before I wrote a single line of code, I outlined the app’s core features:
• Workout Builder: A simple, intuitive interface to design interval workouts.
• Seamless Syncing: Automatically sync workouts from the iPhone to the Watch.
• Real-Time Feedback: Provide clear instructions and progress updates during the run.
I started sketching wireframes and mapping user flows. How would the user add intervals? How would they edit and preview workouts? These questions shaped the design.
Week 2–3: The iPhone Experience
I began by building the iPhone interface using SwiftUI. This allowed me to rapidly prototype and refine the user interface. The Workout Builder became the heart of the app, where users could:
• Add intervals for running, recovery, warm-up, and cool-down.
• Set goals based on time, distance, or heart rate.
• Preview and save the entire workout.
Week 4: Apple Watch Integration with WorkoutKit
The WorkoutKit SDK, introduced in iOS 17 and watchOS 10, became the backbone of the Watch functionality. With it, I could:
• Build a custom workout session for the Apple Watch.
• Provide haptic feedback and voice prompts during intervals.
• Track metrics like heart rate, pace, and distance in real-time.
Week 5: Testing and Feedback
To ensure Run Ri Run met real-world needs, I tested it rigorously:
• My wife used the app during her training sessions, providing invaluable feedback on usability and accuracy.
• I shared a beta version with friends and family, collecting insights on what worked and what needed improvement.
Key feedback led to:
• Standard pace settings: Choose from pre-defined pace settings for an interval goal.
• Single workout steps: Add an individual workout step, for example for a 40-minute easy pace training.
Week 6: Polishing the Details
In the final stretch, I focused on the little things that make a big difference:
• Localization: Prepared the app for future support in multiple languages.
I also fine-tuned the App Store listing with screenshots, a description, and a promo video to showcase the app.
Week 7: Launch Day
With everything in place, I submitted Run Ri Run to the App Store. Waiting for approval was nerve-wracking, but when the green light came, it felt amazing to see the app go live—just days before the Seven Hills Run.
Race Day: Seeing Run Ri Run in Action
The real reward came on race day. My wife completed the Seven Hills Run, and watching her use Run Ri Run to guide her through her final training sessions was incredibly fulfilling. It was a proud moment to see something I built play a role in her success.
What’s Next for Run Ri Run
While the app is now live, this is just the beginning. Future updates will include:
• Widgets: Add a widget to show today’s planned workout for quick access.
• Training Plans: Provide pre-made plans for popular race distances.
Closing Thoughts
Developing Run Ri Run was a labor of love. It combined my passion for running, technology, and problem-solving into one project. Most importantly, it started as a way to make my wife’s training easier—and ended up becoming a tool that any runner can use to achieve their goals.
If you’re a runner looking for a smarter, more intuitive way to train, I invite you to give Run Ri Run a try. Whether you’re preparing for a race or just staying active, it’s designed to help you every step of the way.
Download Run Ri Run
Happy running! 🏃♀️🏃♂️